Statement to Certificateholder

Distribution Information

Deal Information

1. Distribution Summary

Deal Name:

Residential Asset Securities Corp, 2007-KS1

2. Factor Summary

Asset Type:

Home Equity Mortgage Asset Backed Pass-Through
Certificates

3. Components Information

(Not Applicable)

Closing Date:

02/08/2007

4. Interest Summary

First Distribution Date:

02/25/2007

5. Other Income Detail

Determination Date:

05/21/2007

6. Interest Shortfalls, Compensation and Expenses

Distribution Date:

05/25/2007

Record Date:

7. Prepayment Interest and Basis Risk/Net WAC Shortfall Amounts

Book-Entry:

05/24/2007

8. Collateral Summary

Definitive:

04/30/2007

9. Repurchase Information

10. Loan Status Report (Delinquencies)

Trustee:

Us Bank, Inc.

11. Deal Delinquencies (30 Day Buckets)

Main Telephone:

651-495-7000

12. Loss Mitigation and Servicing Modifications

GMAC-RFC

13. Losses and Recoveries

Bond Administrator:

Perry Bons

14. Credit Enhancement Report

Telephone:

818-260-1441

15. Distribution Percentages

(Not Applicable)

Pool(s) :

40475,40476

16. Overcollateralization Summary

17. Excess Cash Flow, Overcollateralization
Provisions and Derivative Amounts

18. Performance Tests

19. Lender Paid Mortgage Insurance

(Not Applicable)

20. Comments

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 1 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



	1. Distribution Summary

			Class	CUSIP			Original Face Value		Beginning Notional / Principal Balance	Pass - Through Rate					Principal Distribution				Interest Distribution			Total Distribution (3) + (4) = (5)			Principal Loss			Interest Loss		Deferred Interest			Ending Notional/ Principal Balance (1)-(3)-(6)+(8)=(9)





									(1)	(2)			(3)					(4)					(5)		(6)		(7)				(8)			(9)

A-1				74924SAA4	172,312,000.00			163,306,467.93			5.38000000			3,971,019.49			732,157.33				4,703,176.82			0.00		0.00			0.00			159,335,448.44


A-2				74924SAB2	51,417,000.00			51,417,000.00			5.42000000			0.00			232,233.45				232,233.45			0.00		0.00			0.00			51,417,000.00


A-3				74924SAC0	79,455,000.00			79,455,000.00			5.47000000			0.00			362,182.38				362,182.38			0.00		0.00			0.00			79,455,000.00


A-4				74924SAD8	29,316,000.00			29,316,000.00			5.54000000			0.00			135,342.20				135,342.20			0.00		0.00			0.00			29,316,000.00


M-1S				74924SAE6	16,074,000.00			16,074,000.00			5.56000000			0.00			74,476.20				74,476.20			0.00		0.00			0.00			16,074,000.00


M-2S				74924SAF3	14,382,000.00			14,382,000.00			5.59000000			0.00			66,996.15				66,996.15			0.00		0.00			0.00			14,382,000.00


M-3S				74924SAG1	8,462,000.00			8,462,000.00			5.63000000			0.00			39,700.88				39,700.88			0.00		0.00			0.00			8,462,000.00


M-4				74924SAH9	7,826,000.00			7,826,000.00			5.69000000			0.00			37,108.28				37,108.28			0.00		0.00			0.00			7,826,000.00


M-5				74924SAJ5	7,614,000.00			7,614,000.00			5.70000000			0.00			36,166.50				36,166.50			0.00		0.00			0.00			7,614,000.00


M-6				74924SAK2	6,768,000.00			6,768,000.00			5.77000000			0.00			32,542.80				32,542.80			0.00		0.00			0.00			6,768,000.00


M-7				74924SAL0	6,768,000.00			6,768,000.00			6.27000000			0.00			35,362.80				35,362.80			0.00		0.00			0.00			6,768,000.00


M-8				74924SAM8	4,864,000.00			4,864,000.00			6.87000000			0.00			27,846.40				27,846.40			0.00		0.00			0.00			4,864,000.00


M-9				74924SAN6	4,441,000.00			4,441,000.00			7.32000000			0.00			27,090.10				27,090.10			0.00		0.00			0.00			4,441,000.00


B				74924SAP1	5,922,000.00			5,922,000.00			7.32000000			0.00			36,124.20				36,124.20			0.00		0.00			0.00			5,922,000.00


SB					7,407,359.83			7,402,996.30			0.00000000			0.00			917,620.83				917,620.83			0.00		0.00			0.00			7,402,996.30


R					0.00			0.00			0.00000000			0.00			0.00				0.00			0.00		0.00			0.00			0.00


		Deal Totals				423,028,359.83		414,018,464.23				3,971,019.49				2,792,950.50				6,763,969.99				0.00		0.00			0.00			410,047,444.74

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 2 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



2. Factor Summary
Amount /Original Amount per $1000 unit)

	Class			CUSIP		Beginning Notional/ Principal Balance Factor	Principal Distribution Factor	Interest Distribution Factor	Total Distribution Factor		Deferred Interest Factor	Interest Shortfall Factor	Ending Notional/ Principal Balance Factor




	A-1			74924SAA4	947.73705795		23.04551912	4.24902114		27.29454025	0.00000000	0.00000000	924.69153884

	A-2			74924SAB2	1,000.00000000		0.00000000	4.51666667		4.51666667	0.00000000	0.00000000	1,000.00000000

	A-3			74924SAC0	1,000.00000000		0.00000000	4.55833340		4.55833340	0.00000000	0.00000000	1,000.00000000

	A-4			74924SAD8	1,000.00000000		0.00000000	4.61666667		4.61666667	0.00000000	0.00000000	1,000.00000000

	M-1S			74924SAE6	1,000.00000000		0.00000000	4.63333333		4.63333333	0.00000000	0.00000000	1,000.00000000

	M-2S			74924SAF3	1,000.00000000		0.00000000	4.65833333		4.65833333	0.00000000	0.00000000	1,000.00000000

	M-3S			74924SAG1	1,000.00000000		0.00000000	4.69166627		4.69166627	0.00000000	0.00000000	1,000.00000000

	M-4			74924SAH9	1,000.00000000		0.00000000	4.74166624		4.74166624	0.00000000	0.00000000	1,000.00000000

	M-5			74924SAJ5	1,000.00000000		0.00000000	4.75000000		4.75000000	0.00000000	0.00000000	1,000.00000000

	M-6			74924SAK2	1,000.00000000		0.00000000	4.80833333		4.80833333	0.00000000	0.00000000	1,000.00000000

	M-7			74924SAL0	1,000.00000000		0.00000000	5.22500000		5.22500000	0.00000000	0.00000000	1,000.00000000

	M-8			74924SAM8	1,000.00000000		0.00000000	5.72500000		5.72500000	0.00000000	0.00000000	1,000.00000000

	M-9			74924SAN6	1,000.00000000		0.00000000	6.10000000		6.10000000	0.00000000	0.00000000	1,000.00000000

	B			74924SAP1	1,000.00000000		0.00000000	6.10000000		6.10000000	0.00000000	0.00000000	1,000.00000000

	SB		1

	R				0.00000000		0.00000000	0.00000000		0.00000000	0.00000000	0.00000000	0.00000000

	1	Factors not reported for OC Classes



	Deal Factor :			96.93143148%


	Group I Factor :			98.04056274%


	Group II Factor :			96.48025089%

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 3 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



4. Interest Summary
The following section only reports information for classes that have accrued interest for this distribution.

Class		Accrual Period			Accrual Methodology	Beginning Notional/Principal Balance		Pass- Through Rate	Optimal Interest		Interest Loss			Deferred Interest		Interest Shortfall Amount		Other Income		Interest Distribution (1)-(2)-(3)- (4)+(5)=(6)		Accrued Certificate Interest Remaining Unpaid






		Start		End						(1)		(2)			(3)		(4)		(5)		(6)
A-1	04/25/2007		05/24/2007		Actual/360		163,306,467.93	5.38000000	732,157.33		0.00		0.00			0.00		0.00		732,157.33		0.00

A-2	04/25/2007		05/24/2007		Actual/360		51,417,000.00	5.42000000	232,233.45		0.00		0.00			0.00		0.00		232,233.45		0.00

A-3	04/25/2007		05/24/2007		Actual/360		79,455,000.00	5.47000000	362,182.38		0.00		0.00			0.00		0.00		362,182.38		0.00

A-4	04/25/2007		05/24/2007		Actual/360		29,316,000.00	5.54000000	135,342.20		0.00		0.00			0.00		0.00		135,342.20		0.00

M-1S	04/25/2007		05/24/2007		Actual/360		16,074,000.00	5.56000000	74,476.20		0.00		0.00			0.00		0.00		74,476.20		0.00

M-2S	04/25/2007		05/24/2007		Actual/360		14,382,000.00	5.59000000	66,996.15		0.00		0.00			0.00		0.00		66,996.15		0.00

M-3S	04/25/2007		05/24/2007		Actual/360		8,462,000.00	5.63000000	39,700.88		0.00		0.00			0.00		0.00		39,700.88		0.00

M-4	04/25/2007		05/24/2007		Actual/360		7,826,000.00	5.69000000	37,108.28		0.00		0.00			0.00		0.00		37,108.28		0.00

M-5	04/25/2007		05/24/2007		Actual/360		7,614,000.00	5.70000000	36,166.50		0.00		0.00			0.00		0.00		36,166.50		0.00

M-6	04/25/2007		05/24/2007		Actual/360		6,768,000.00	5.77000000	32,542.80		0.00		0.00			0.00		0.00		32,542.80		0.00

M-7	04/25/2007		05/24/2007		Actual/360		6,768,000.00	6.27000000	35,362.80		0.00		0.00			0.00		0.00		35,362.80		0.00

M-8	04/25/2007		05/24/2007		Actual/360		4,864,000.00	6.87000000	27,846.40		0.00		0.00			0.00		0.00		27,846.40		0.00

M-9	04/25/2007		05/24/2007		Actual/360		4,441,000.00	7.32000000	27,090.10		0.00		0.00			0.00		0.00		27,090.10		0.00

B	04/25/2007		05/24/2007		Actual/360		5,922,000.00	7.32000000	36,124.20		0.00		0.00			0.00		0.00		36,124.20		0.00

SB	04/01/2007		04/30/2007		Actual/360		7,402,996.30	0.00000000	0.00		0.00		0.00			0.00		917,620.83		917,620.83		0.00

Deal Totals						414,018,464.23			1,875,329.67		0.00		0.00			0.00		917,620.83		2,792,950.50		0.00



	Current Index Rates

Index Type		Rate		Classes


USLIB TEL 25 -2BD		5.32000000	A-1, A-2, A-3, B, M-1S, M-3S, M-5, M-7, M-8, M-6, M-4, M-2S, M-9, A-4

5. Other Income Detail

Class

Prepayment Charges

Remaining Excess Cash Flow
and OC Release Amount

Other Income Distribution

(1)

(2)

(1) + (2) = (3)

36,274.70

881,346.13

917,620.83

Deal Totals

36,274.70

881,346.13

917,620.83

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 4 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007


6. Interest Shortfalls, Compensation and Expenses

			Current Prepayment Interest Shortfall Amount		Compensating Interest			Net Prepayment Interest Shortfall Amount (1) - (2)=(3)		Civil Relief Act	Civil Relief Act	Compensation				Advances			Allowable Expenses per	Non - Recoverable Advances





			(1)			(2)			(3)			Subservicer		Master		Subservicer		Master



	Group I	6,450.99		9,716.26			-3,265.27			0	0.00		45,170.37		0.00		9,097.32	0.00	0.00	0.00

	Group II	9,716.26		6,450.99			3,265.27			0	0.00		109,152.92		5,893.13		70,295.18	0.00	0.00	0.00

	Deal Totals	16,167.25		16,167.25			0.00			0	0.00		154,323.29		5,893.13		79,392.50	0.00	0.00	0.00



7. Prepayment Interest and Basis Risk/Net WAC Shortfall Amounts

(A) Prepayment Interest Shortfall Amounts														(B) Basis Risk/Net WAC Shortfall Amounts

Class			Current		Prior Unpaid		Prior Unpaid Accrued Interest		Total Paid		Remaining Unpaid (1)+(2)+(3)-(4)=(5)		Current Period Uncompensated			Prior Unpaid		Prior Unpaid Accrued Interest		Total Paid		Remaining Unpaid (1)+(2)+(3)-(4)=(5)




			(1)		(2)		(3)		(4)		(5)		(1)			(2)		(3)		(4)		(5)

	A-1		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	A-2		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	A-3		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	A-4		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-1S		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-2S		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-3S		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-4		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-5		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-6		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-7		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-8		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	M-9		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	B		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	SB		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

	R		0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00


	Deal Totals	0.00		0.00		0.00		0.00		0.00		0.00			0.00		0.00		0.00		0.00

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 5 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



8. Collateral Summary

A. Loan Count and Balances

								Original Loan Count/ Scheduled Principal Balance							Beginning Loan Count/ Scheduled Principal Balance						Scheduled Principal			Curtailments					Payoffs					Matured Loans		Repurchases			Beginning Aggregate Scheduled Principal Balance of Liquidations/ Charge-offs					Ending Loan Count/Scheduled Principal Balance




			Count								1,191					1,181			N/A						165						12				0			0				0				1,169
		Group I


			Balance/Amount				122,323,100.18							121,289,347.67					66,510.06							8,919.52				1,287,662.31				N/A			0.00		0.00						119,926,255.78



			Count								1,584					1,553			N/A						169						14				0			0				0				1,539
		Group II


			Balance/Amount				300,705,259.65							292,729,116.56					113,685.42							31,601.08				2,462,641.10				N/A			0.00		0.00						290,121,188.96



		Deal Totals	Count							2,775							2,734				N/A				334				26					0		0					0						2,708


			Balance/Amount			423,028,359.83							414,018,464.23							180,195.48					40,520.60				3,750,303.41					N/A		0.00				0.00			410,047,444.74




B. Weighted Averages

			Beginning Weighted Average Gross Mortgage Rate	Ending Weighted Average Gross Mortgage Rate					Ending Weighted Average Remaining Amortization Term			Ending Weighted Average Months to Maturity						Beginning Weighted Average Net Mortgage					Ending Weighted Average Net Mortgage		Beginning Weighted Average Unmodified Net Mortgage			Net Weighted Average Cap Rate				Weighted Average Net Rate

		Group I
			8.86490236	8.85851949					380.14			336.43						8.36484409					8.35846971		8.36484409			7.99000828					7.99000828

		Group II
			8.33457839	8.33820594					405.54			353.44						7.83469886					7.83832742		7.83469886			7.99000828					7.99000828

		Deal Totals
			8.48994018	8.49038164					398.11			348.46						7.99000828					7.99045303		7.99000828			N/A					N/A



C. Constant Prepayment Rate

			1 Month CPR		3 Month CPR							6 Month CPR										12 Month CPR					Life CPR


	Group-I		12.11%		6.58%																						5.15%

	Group-II		9.76%		12.40%																						9.78%

	Deal Totals		10.45%		10.74%																						8.45%

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 6 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



9. Repurchases

			Breaches Of Representations			ARM Conversions		Optional Repurchases of Defaulted Loans		Others		Total (1)+(2)+(3)+(4)=(5)
				(1)	(2)		(3)			(4)		(5)
		Count				0			0		0		0
				0


	Group I
		Scheduled Balance		0.00		0.00			0.00		0.00			0.00


		Count				0			0		0		0
				0


	Group II
		Scheduled Balance		0.00		0.00			0.00		0.00			0.00



		Count		0		0			0		0		0
	Deal Totals


		Scheduled Balance		0.00		0.00			0.00		0.00		0.00

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 7 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007


10. Loan Status Report
													Delinquency Calculation Method: Office of Thrift Supervision

					Current / Delinquent																	Bankruptcy								Foreclosure								REO																Total
	Deal Totals

		Count								Scheduled Balance					Count				Scheduled Balance				Count				Scheduled Balance					Count			Scheduled Balance				Actual Balance						Count								Scheduled Balance

	Current						2,650				398,934,547.38				4			282,603.60								0			0.00				0				0.00							0.00						2,654		399,217,150.98

	30 days					39					7,706,276.97				1			30,415.09								0			0.00				0				0.00							0.00						40		7,736,692.06

	60 days					13					2,959,538.47				0			0.00								0			0.00				0				0.00							0.00						13		2,959,538.47

	90 days					0					0.00				0			0.00								1			134,063.23				0				0.00							0.00						1		134,063.23

	120 days					0					0.00				0			0.00								0			0.00				0				0.00							0.00						0		0.00

	150 days					0					0.00				0			0.00								0			0.00				0				0.00							0.00						0		0.00

	180 days					0					0.00				0			0.00								0			0.00				0				0.00							0.00						0		0.00

	181+ days					0					0.00				0			0.00								0			0.00				0				0.00							0.00						0		0.00

	Total							2,702			409,600,362.82				5		313,018.69								1			134,063.23			0					0.00					0.00						2,708				410,047,444.74


	Current			97.86%								97.29%			0.15%						0.07%				0.00%				0.00%				0.00%		0.00%							0.00%								98.01%		97.36%

	30 days					1.44%					1.88%				0.04%						0.01%				0.00%				0.00%				0.00%		0.00%							0.00%							1.48%			1.89%

	60 days					0.48%					0.72%				0.00%						0.00%				0.00%				0.00%				0.00%		0.00%							0.00%							0.48%			0.72%

	90 days					0.00%					0.00%				0.00%						0.00%				0.04%				0.03%				0.00%		0.00%							0.00%							0.04%			0.03%

	120 days					0.00%					0.00%				0.00%						0.00%				0.00%				0.00%				0.00%		0.00%							0.00%							0.00%			0.00%

	150 days					0.00%					0.00%				0.00%						0.00%				0.00%				0.00%				0.00%		0.00%							0.00%							0.00%			0.00%

	180 days					0.00%					0.00%				0.00%						0.00%				0.00%				0.00%				0.00%		0.00%							0.00%						0.00%				0.00%

	181+ days					0.00%					0.00%				0.00%					0.00%					0.00%				0.00%				0.00%		0.00%								0.00%						0.00%			0.00%

	Total		99.78%						99.89%					0.18%		0.08%								0.04%				0.03%			0.00%			0.00%						0.00%						100.00%					100.00%

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 8 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



			Current / Delinquent											Bankruptcy						Foreclosure					REO											Total
Group I

	Count						Scheduled Balance							Count			Scheduled Balance	Count				Scheduled Balance					Count			Scheduled Balance	Actual Balance				Count					Scheduled Balance


Current						1,152						118,767,769.31		2		90,363.93					0			0.00				0		0.00			0.00					1,154			118,858,133.24

30 days					11					836,327.18			1			30,415.09					0			0.00				0		0.00			0.00					12			866,742.27

60 days					3					201,380.27			0			0.00					0			0.00				0		0.00			0.00					3			201,380.27

90 days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

120 days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

150 days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

180 days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

181+ days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

Total					1,166					119,805,476.76			3			120,779.02				0				0.00				0		0.00				0.00				1,169			119,926,255.78


Current				98.55%				99.03%						0.17%		0.08%				0.00%				0.00%				0.00%		0.00%				0.00%				98.72%			99.11%

30 days				0.94%							0.70%		0.09%			0.03%				0.00%				0.00%				0.00%		0.00%				0.00%				1.03%				0.72%

60 days				0.26%							0.17%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.26%		0.17%

90 days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

120 days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

150 days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

180 days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

181+ days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

Total		99.74%							99.90%				0.26%		0.10%				0.00%				0.00%			0.00%			0.00%			0.00%					100.00%		100.00%

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 9 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



			Current / Delinquent											Bankruptcy						Foreclosure					REO											Total
Group II

	Count						Scheduled Balance							Count			Scheduled Balance	Count				Scheduled Balance					Count			Scheduled Balance	Actual Balance				Count					Scheduled Balance


Current						1,498						280,166,778.07		2		192,239.67					0			0.00				0		0.00			0.00					1,500			280,359,017.74

30 days					28					6,869,949.79			0			0.00					0			0.00				0		0.00			0.00					28			6,869,949.79

60 days					10					2,758,158.20			0			0.00					0			0.00				0		0.00			0.00					10			2,758,158.20

90 days					0					0.00			0			0.00					1			134,063.23				0		0.00			0.00					1			134,063.23

120 days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

150 days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

180 days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

181+ days					0					0.00			0			0.00					0			0.00				0		0.00			0.00					0			0.00

Total					1,536					289,794,886.06			2			192,239.67				1				134,063.23				0		0.00				0.00				1,539			290,121,188.96


Current				97.34%				96.57%						0.13%		0.07%				0.00%				0.00%				0.00%		0.00%				0.00%				97.47%			96.64%

30 days				1.82%							2.37%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				1.82%				2.37%

60 days				0.65%							0.95%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.65%		0.95%

90 days				0.00%							0.00%		0.00%			0.00%				0.06%				0.05%				0.00%		0.00%				0.00%				0.06%		0.05%

120 days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

150 days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

180 days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

181+ days				0.00%							0.00%		0.00%			0.00%				0.00%				0.00%				0.00%		0.00%				0.00%				0.00%		0.00%

Total		99.81%							99.89%				0.13%		0.07%				0.06%				0.05%			0.00%			0.00%			0.00%					100.00%		100.00%

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 10 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



11. Delinquency Data

			Totals				Totals					Totals					Totals					Totals
		Count % Count		Balance % Balance		Count % Count		Balance % Balance			Count % Count		Balance % Balance			Count % Count		Balance % Balance			Count % Count		Balance % Balance

			40	7,736,692.06			0		0.00			0		0.00			0		0.00			0		0.00
	1 Month				13 Months					25 Months					37 Months					49 Months


			1.48%	1.89%			0.00%	0.00%				0.00%		0.00%			0.00%		0.00%			0.00%		0.00%


			13	2,959,538.47			0		0.00			0		0.00			0		0.00			0		0.00
	2 Months				14 Months					26 Months					38 Months					50 Months


			0.48%	0.72%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%


			1	134,063.23			0		0.00			0		0.00			0		0.00			0		0.00
	3 Months				15 Months					27 Months					39 Months					51 Months


			0.04%	0.03%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%


			0	0.00			0		0.00			0		0.00			0		0.00			0		0.00
	4 Months				16 Months					28 Months					40 Months					52 Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%


			0	0.00			0		0.00			0		0.00			0		0.00			0		0.00
	5 Months				17 Months					29 Months					41 Months					53 Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%


			0	0.00			0		0.00			0		0.00			0		0.00			0		0.00
	6 Months				18 Months					30 Months					42 Months					54 Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%

			0	0.00			0		0.00			0		0.00			0		0.00			0		0.00
	7 Months				19 Months					31 Months					43 Months					55 Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%

																	0		0.00
			0	0.00			0		0.00			0		0.00								0		0.00

	8 Months				20 Months					32 Months					44 Months					56 Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%


			0	0.00			0		0.00			0		0.00			0		0.00			0		0.00
	9 Months				21 Months					33 Months					45 Months					57 Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%


			0	0.00			0		0.00			0		0.00			0		0.00			0		0.00
	10 Months				22 Months					34 Months					46 Months					58 Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%

														0.00					0.00
			0	0.00			0		0.00			0					0					0		0.00

	11 Months				23 Months					35 Months					47 Months					59 Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%

			0	0.00			0		0.00			0		0.00			0		0.00			0		0.00
	12 Months				24 Months					36 Months					48 Months					60+ Months


			0.00%	0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%			0.00%		0.00%

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 11 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



12. Loss Mitigation and Servicing Modifications


			Current			1 Payment			2 Payments				3+ Payments				Foreclosure				REO		Total

		Modification Type	Count		Scheduled Balance	Count		Scheduled Balance	Count			Scheduled Balance	Count		Scheduled Balance		Count	Scheduled Balance			Count	Scheduled Balance	Count	Scheduled Balance


Group I		Capitalizations	0		0.00	0		0.00		0		0.00		0		0.00	0		0.00	0		0.00	0	0.00


		Other Modifications	0		0.00	0		0.00		0		0.00		0		0.00	0		0.00	0		0.00	0	0.00



Group II		Capitalizations	0		0.00	0		0.00		0		0.00		0		0.00	0		0.00	0		0.00	0	0.00


		Other Modifications	0		0.00	0		0.00		0		0.00		0		0.00	0		0.00	0		0.00	0	0.00



		Capitalizations		0	0.00		0	0.00			0	0.00		0		0.00	0		0.00	0		0.00	0	0.00

	Deal Totals
		Other
				0	0.00		0	0.00			0	0.00		0		0.00	0		0.00	0		0.00	0	0.00



				Payoffs										Repurchases					Liquidations													Total

		Current Month					Cumulative						Current Month			Cumulative			Current Month				Cumulative								Current Month						Cumulative
Modification Type

		Count			Scheduled Balance		Count		Scheduled Balance			Count			Scheduled Balance	Count	Scheduled Balance	Count		Scheduled Balance			Count		Scheduled Balance					Count					Scheduled Balance		Count		Scheduled Balance


Group I	Capitalizations		0		0.00		0			0.00			0		0.00	0	0.00	0		0.00			0				0.00			0					0.00		0				0.00


	Other Modifications		0		0.00		0			0.00			0		0.00	0	0.00	0		0.00			0				0.00			0					0.00		0		0.00



Group II	Capitalizations		0		0.00		0			0.00			0		0.00	0	0.00	0		0.00			0				0.00			0					0.00		0				0.00


	Other Modifications		0		0.00		0			0.00			0		0.00	0	0.00	0		0.00			0				0.00			0					0.00		0		0.00



Deal Totals	Capitalizations		0		0.00		0			0.00			0		0.00	0	0.00	0		0.00		0				0.00			0					0.00		0				0.00


	Other Modifications

		0		0.00		0		0.00			0			0.00	0	0.00	0		0.00		0			0.00				0					0.00		0			0.00

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 12 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



13. Losses and Recoveries
A. Current Cycle Realized Losses

			Current Period Realized Losses		Liquidations					Charge-Offs					Servicing Modifications						Bankruptcy Losses	Total

		Loss Count			0								0					0			0				0


	Group I		Beginning Aggregate Scheduled Balance		0.00								0.00						0.00		0.00				0


		Principal Portion of Loss					0.00							0.00						0.00	0.00					0.00



		Interest Portion of Loss						0.00						0.00						0.00	0.00					0.00


		Total Realized Loss		0.00								0.00					0.00				0.00	0.00


		Loss Count			0								0					0			0				0


	Group II		Beginning Aggregate Scheduled Balance		0.00								0.00						0.00		0.00				0


		Principal Portion of Loss					0.00							0.00						0.00	0.00					0.00



		Interest Portion of Loss						0.00						0.00						0.00	0.00					0.00


		Total Realized Loss		0.00								0.00					0.00				0.00	0.00


		Loss Count							0				0					0			0						0


		Beginning Aggregate Scheduled Balance							0.00				0.00					0.00			0.00						0.00
	Deal Totals



		Principal Portion of Loss							0.00				0.00					0.00			0.00						0.00


		Interest Portion of Loss						0.00					0.00					0.00			0.00						0.00


		Total Realized Loss					0.00				0.00					0.00					0.00			0.00


B. Cumulative Realized Losses

			Cumulative Realized Losses		Liquidations					Charge-Offs					Servicing Modifications						Bankruptcy Losses	Total


	Group I	Loss Count			1								0					0			0				1


		Total Realized Loss				1,575.16								0.00						0.00	0.00					1,575.16



	Group II	Loss Count			0								0					0			0				0


		Total Realized Loss				0.00								0.00						0.00	0.00					0.00



	Deal Totals	Loss Count					1						0					0			0		1


		Total Realized Loss				1,575.16							0.00					0.00			0.00		1,575.16

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 13 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



C. Subsequent Recoveries

				Subsequent Recoveries	Current Period								Cumulative


			Subsequent Recoveries Count				0			0
		Group I
			Subsequent Recoveries					0.00			0.00


			Net Loss 1					0.00				1,575.16


			Net Loss % 2						0.00%					0.00%


			Subsequent Recoveries Count				0			0
		Group II
			Subsequent Recoveries					0.00			0.00


			Net Loss 1					0.00				0.00


			Net Loss % 2						0.00%					0.00%


			Subsequent Recoveries Count					0		0


			Subsequent Recoveries					0.00		0.00
		Deal Totals


			Net Loss 1					0.00		1,575.16



			Net Loss % 2			0.00%				0.00%

	1 Total Realized Loss less Subsequent Recoveries
	2 Net Loss % of Original Balance

D. Default Percentages

Default Loss Percentage

1 Month

3 Months

6 Months

12 Months

Life of Deal

Group

Monthly Default Rate

0.00%

0.02%

Constant Default Rate

0.00%

0.28%

0.21%

Group

Monthly Default Rate

0.00%

Constant Default Rate

0.00%

Monthly Default Rate

0.00%

0.01%

Deal Totals

Constant Default Rate

0.00%

0.08%

0.06%

1-Month MDR (Current Month) = SUM(Beginning Scheduled balances of liquidating loans) / [SUM(Beginning Scheduled loan balances)- SUM(Scheduled Principal payments)]
m-Month = 3, 6, 12, months or the life of deal to date
m-Month MDR(over m months in period where n is current month)= 1-[(1-MDRn-m+1) * (1-MDRn-m+2) *.* (1-MDR n-1) * (1-MDRn)]^(1/m)
CDRm = 1- [(1- MDRm)^12],where m is number of months in period

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 14 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007

14. Credit Enhancement Report

Reserve Accounts

DEPOSITS

WITHDRAWALS

Ending
Balance

Description

Source

Beginning
Balance

Investment
Earnings

Other
Deposits

Draws

Releases

Supplemental Interest Trust

0.00

Hedge Agreements

Description

Provider

Termination
Date

Amount Received From Provider

Amount Paid to Provider

Swap Agreement

Bear, Stearns & Co., Inc.

06/25/2011

0.00

Yield Maintenance Agreement

Bear, Stearns & Co., Inc.

06/25/2011

0.00

Corridor Agreement Class A's

Bear, Stearns & Co., Inc.

07/25/2007

0.00

Corridor Agreement Class M's & B

Bear, Stearns & Co., Inc.

07/25/2007

0.00



16. Overcollateralization Summary

		Prior Required Overcollateralization Amount	Beginning Overcollateralization Amount	Overcollateralization Increase/(Reduction) Amount		Ending Overcollateralization Amount		Current Required Overcollateralization Amount
	Deal Total
		7,402,996.30	7,402,996.30		0.00		7,402,996.30	7,402,996.30

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 15 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



17. Excess Cashflow, Overcollateralization and Derivative Amounts

	Excess Cashflow and Derivative Summary

	(1)	Scheduled Unmodified Net Interest	2,756,675.80


	(2)	Interest Losses	0.00


	(3)	Subsequent Recoveries	0.00


	(4)	Interest Adjustment Amount	0.00


	(5)	Yield Maintenance/Corridor/Swap Payment Amount - IN	0.00


	(6)	Yield Maintenance/Corridor/Swap Payment Amount - OUT	0.00


	(7)	Certificate Interest Amount	1,875,329.67


	(8)	OC Reduction Amount	0.00


	(9)	Excess Cashflow Prior to OC Provisions	881,346.13


	Overcollateralization and Derivative Amounts

		Excess Cashflow Prior to OC Provisions	881,346.13


	(1)	Basis Risk Shortfall covered by Yield Maintenance Agreement	0.00


	(2)	Unreimbursed Principal Portion of Realized Losses	0.00


	(3)	Principal Portion of Realized Losses	0.00


	(4)	Overcollateralization Increase	0.00


	(5)	Prepayment Interest Shortfall	0.00


	(6)	Unpaid PPIS With Accrued Interest	0.00


	(7)	Basis Risk Shortfall Carry-Forward Amount	0.00


	(8)	Relief Act Shortfall	0.00


	(9)	Unreimbursed Realized Losses	0.00


	(10)	Swap Termination Payment Amount	0.00


	(11)	To Class SB Certificates	881,346.13

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 16 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007


18. Performance Tests


	Senior Balance Test

		Senior Certificate Beginning Balance - Actual Value	323,494,467.93

		Zero Balance	0.00

		Senior Certificate Beginning Balance = 0.00	False

	Current Distribution Date >= Target Distribution

		Current Distribution Period	4

		StepDownTarget Distribution Period	37

		Current Distribution Date >= Target Distribution Date	False

	Stepdown Date - Senior Enhancement Test

		Current Senior Enhancement Percent - Actual value	22.07646900%

		Specified Senior Enhancement Percent - Target value	42.80000000%

		Senior Enhance Pct >= Specified Senior Enhance Pct (Actual End Balance <= Target End Balance)	False

	StepDown Date and Senior Enhancement pass

		Current Distribution Date >= Target Distribution Date	False

		Senior Enhance Pct >= Specified Senior Enhance Pct (Actual End Balance <= Target End Balance)	False

		After StepDown Date and Senior Enh Percent >= Target Percent	False

	StepDown Date has occured

		Senior Certificate Beginning Balance = 0.00	False

		After StepDown Date and Senior Enh Percent >= Target Percent	False

		Stepdown Date has occurred	False

	Sixty-Plus Delinquency Percentage >= Target %

		3-Month Average Sixty-Plus Delinquency Percentage - Actual Value	0.26438000%

		Senior Enhancement Delinquency Percentage - Target Value	8.25218400%

		Sixty-Plus Delinquency Percentage >= Senior Enhancement Delinquency Percentage Target	False

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 17 of 18

Statement to Certificateholder

Residential Asset Securities Corp, 2007-KS1

May 25, 2007



Trigger Event clause (b) - Realized Loss Test

	Aggregate Realized Loss Percentage - Actual Value	0.00037200%

	Scheduled Loss Target Percent	99,999.00000000%

	Aggregate Realized Loss Percentage >= Scheduled Loss Percent	False

Trigger Event is in effect?

	Sixty-Plus Delinquency Percentage >= Senior Enhancement Delinquency Percentage Target	False

	Aggregate Realized Loss Percentage >= Scheduled Loss Percent	False

	Trigger Event is in effect	False

Stepdown Date and Trigger Event in effect

	Stepdown Date has occurred	False

	Trigger Event is in effect	False

	Trigger Event is in effect on or after StepDown Date	False



20. Comments

	ERISA Text:	Each beneficial owner of any Certificate (or any interest therein) which provides credit enhancement for any other Certificate and is available in book-entry form, including any such

		Class M Certificate, shall be deemed to have represented, by virtue of its acquisition or holding of such Certificate (or interest therein), that either: a) it is not an employee benefit
		or other plan subject to the prohibited transaction provision of the Employee Retirement Income Security Act of 1974, as amended('ERISA'), or Section 4975 of the Internal Revenue
		Code of 1986, as amended (a 'Plan'), or any other person (including an investment manager, a named fiduciary or a trustee of any Plan) acting, directly or indirectly, on behalf of
		purchasing any Certificate with 'plan assets' of any Plan; or b) (i) the transferee is an insurance company, (ii) the source of funds to be used by it to purchase the Certificates is an
		'insurance company general account' (within the meaning of Department of Labor Prohibited Transaction Class Exemption ('PTCE') 95-60), and (iii) the conditions set forth in
		Section I and III of PTCE 95-60 have been satisfied. Any purported beneficial owner of any such book-entry Certificate (or interest therein) to whom either (a) or (b) above does not
		apply shall indemnify and hold harmless the Company, the Trustee, the Master Servicer, any Subservicer, and the Trust Fund from and against any and all liabilities, claim, cost or
		expenses incurred by such parties as a result of its acquisition or holding of such Certificate.

05/29/2007

3:17:19PM

Residential Funding Company, LLC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors

Page 18 of 18



	Statement To Certificateholder



	Residential Asset Securities Corp., 2007-KS1

	May 25, 2007



	Cash Flow Received and Uses of Funds


	Cash Flow Received		Amount

	Principal and Interest Payments		6,717,421.17
	Prepayment Premium		36,274.70
	Liquidation and Insurance Proceeds		0.00
	Subsequent Recoveries		0.00
	Repurchase Proceeds		0.00
	Other Deposits/Adjustments (including Derivatives Payment)		16,167.25
	Total Deposits		6,769,863.12

	Uses of Funds		Amount

	Transfer to Certificate Account		6,763,969.99
	Reimbursed Advances and Expenses		0.00
	Master Servicing Compensation		5,893.13
	Derivatives Payment		0.00
	Total Withdrawals		6,769,863.12

	Ending Balance		0.00



		GMAC-RFC, 2255 North Ontario Street, Suite 400, Burbank, CA 91504, 818.260.1400, www.gmacrfc.com/investors	Appendix A

RASC Series 2007-KS1 Trust 10-D