Structured  Asset Securities Corporation  Mortgage Pass-Through Certificates,  Series
2004-S1
Distribution Date:          12/27/2004
Record Date:                11/30/2004

Distribution Summary

DISTRIBUTION IN DOLLARS

                                                  Prior         Pass-                                                                                       Current
                            Original              Principal     Through       Interest    Principal     Total          Deferred               Realized      Principal
Class                       Balance               Balance       Rate          Distributed Distributed   Distributed    Interest               Loss          Balance
(1)                         (2)                   (3)           (4)           (5)         (6)           (7)=(5+6)      (8)                    (9)           (10)=(3-6+8-9)

A1                          157,734,000.00        68,642,229.30 2.310000%     136,540.83  13,554,945.37 13,691,486.20  0.00                   0.00          55,087,283.93

A2                          18,486,000.00         18,486,000.00 2.530000%     40,273.81   0.00          40,273.81      0.00                   0.00          18,486,000.00

M1                          23,285,000.00         23,285,000.00 2.730000%     54,739.15   0.00          54,739.15      0.00                   0.00          23,285,000.00

M2                          19,509,000.00         19,509,000.00 3.330000%     55,942.06   0.00          55,942.06      0.00                   0.00          19,509,000.00

M3                          11,328,000.00         11,328,000.00 3.680000%     35,897.17   0.00          35,897.17      0.00                   0.00          11,328,000.00

M4                          6,922,000.00          6,922,000.00  3.880000%     23,127.17   0.00          23,127.17      0.00                   0.00          6,922,000.00

M5                          3,650,000.00          3,650,000.00  4.930000%     15,495.26   0.00          15,495.26      0.00                   0.00          3,650,000.00

B1                          6,419,000.00          6,419,000.00  7.000000%     37,444.17   0.00          37,444.17      0.00                   0.00          6,419,000.00

B2                          4,405,000.00          4,405,000.00  7.000000%     25,695.83   0.00          25,695.83      0.00                   0.00          4,405,000.00

X                           221.66                3,438,489.58  0.000000%     0.00        0.00          0.00           936,324.40             0.00          4,374,813.98

P                           100.00                100.00        0.000000%     97,062.28   0.00          97,062.28      0.00                   0.00          100.00

R                           0.00                  0.00          0.000000%     0.00        0.00          0.00           0.00                   0.00          0.00

Totals                      251,738,321.66        166,084,818.88              522,217.73  13,554,945.37 14,077,163.10  0.00                   0.00          138,267,283.93

Distribution Summary (Factors)

PER $1,000 OF ORIGINAL BALANCE

                                                  Prior                                                                                       Current
                                                  Principal     Interest      Principal   Total         Deferred       Realized               Principal
                                                                Distributed
Class                       CUSIP                 Balance       (5/2 x 1000)  Distributed Distributed   Interest       Loss                   Balance
                                                  (3/2 x 1000)                (6/2 x 1000)(7/2 x 1000)  (8/2 x 1000)   (9/2 x 1000)           (10/2 x 1000)

A1                          86359BKR1             435.177129    0.865640      85.935470   86.801109     0.000000       0.000000               349.241660

A2                          86359BKS9             1,000.000000  2.178611      0.000000    2.178611      0.000000       0.000000               1,000.000000

M1                          86359BKT7             1,000.000000  2.350833      0.000000    2.350833      0.000000       0.000000               1,000.000000

M2                          86359BKU4             1,000.000000  2.867500      0.000000    2.867500      0.000000       0.000000               1,000.000000

M3                          86359BKV2             1,000.000000  3.168889      0.000000    3.168889      0.000000       0.000000               1,000.000000

M4                          86359BKW0             1,000.000000  3.341111      0.000000    3.341111      0.000000       0.000000               1,000.000000

M5                          86359BKX8             1,000.000000  4.245277      0.000000    4.245277      0.000000       0.000000               1,000.000000

B1                          86359BLY5             1,000.000000  5.833334      0.000000    5.833334      0.000000       0.000000               1,000.000000

B2                          86359BLZ2             1,000.000000  5.833333      0.000000    5.833333      0.000000       0.000000               1,000.000000

X                                                 ##############0.000000      0.000000    0.000000       ##############0.000000               ##############

P                                                 1,000.000000  970,622.8000000.000000    970,622.8000000.000000       0.000000               1,000.000000

Interest Distribution Detail

DISTRIBUTION IN DOLLARS

                            Prior                 Pass-         Optimal       Prior       Non-Recov                                                         Current
                            Principal             Through       Accrued       Unpaid      Interest      Interest       Deferred               Interest      Unpaid
                                                                                                                                              Distributed
Class                       Balance               Rate          Interest      Interest    Shortfall     Due            Interest               (9)           Interest
(1)                         (2)                   (3)           (4)           (5)         (6)           (7)=(4)+(5)-(6)(8)                                  (10)=(7)-(8)-(9)

A1                          68,642,229.30         2.310000%     136,540.83    0.00        0.00          136,540.83     0.00                   136,540.83    0.00

A2                          18,486,000.00         2.530000%     40,273.81     0.00        0.00          40,273.81      0.00                   40,273.81     0.00

M1                          23,285,000.00         2.730000%     54,739.15     0.00        0.00          54,739.15      0.00                   54,739.15     0.00

M2                          19,509,000.00         3.330000%     55,942.06     0.00        0.00          55,942.06      0.00                   55,942.06     0.00

M3                          11,328,000.00         3.680000%     35,897.17     0.00        0.00          35,897.17      0.00                   35,897.17     0.00

M4                          6,922,000.00          3.880000%     23,127.17     0.00        0.00          23,127.17      0.00                   23,127.17     0.00

M5                          3,650,000.00          4.930000%     15,495.26     0.00        0.00          15,495.26      0.00                   15,495.26     0.00

B1                          6,419,000.00          7.000000%     37,444.17     0.00        0.00          37,444.17      0.00                   37,444.17     0.00

B2                          4,405,000.00          7.000000%     25,695.83     0.00        0.00          25,695.83      0.00                   25,695.83     0.00

X                           3,438,489.58          0.000000%     936,324.40    0.00        0.00          936,324.40     936,324.40             0.00          0.00

P                           100.00                0.000000%     97,062.28     0.00        0.00          97,062.28      0.00                   97,062.28     0.00

R                           0.00                  0.000000%     0.00          0.00        0.00          0.00           0.00                   0.00          0.00

  Totals                    166,084,818.88                      1,458,542.13  0.00        0.00          1,458,542.13   0.00                   522,217.73    0.00

Principal Distribution
Detail

DISTRIBUTION IN DOLLARS

                                                  Prior                                   Current       Current        Current                Cumulative
                            Original              Principal     Principal     Accreted    Realized      Principal      Principal              Realized
Class                       Balance               Balance       Distribution  Principal   Losses        Recoveries     Balance                Losses
(1)                         (2)                   (3)           (4)           (5)         (6)           (7)            (8)=(3)-(4)+(5)-(6)+(7)(9)

A1                          157,734,000.00        68,642,229.30 13,554,945.37 0.00        0.00          0.00           55,087,283.93          0.00

A2                          18,486,000.00         18,486,000.00 0.00          0.00        0.00          0.00           18,486,000.00          0.00

M1                          23,285,000.00         23,285,000.00 0.00          0.00        0.00          0.00           23,285,000.00          0.00

M2                          19,509,000.00         19,509,000.00 0.00          0.00        0.00          0.00           19,509,000.00          0.00

M3                          11,328,000.00         11,328,000.00 0.00          0.00        0.00          0.00           11,328,000.00          0.00

M4                          6,922,000.00          6,922,000.00  0.00          0.00        0.00          0.00           6,922,000.00           0.00

M5                          3,650,000.00          3,650,000.00  0.00          0.00        0.00          0.00           3,650,000.00           0.00

B1                          6,419,000.00          6,419,000.00  0.00          0.00        0.00          0.00           6,419,000.00           0.00

B2                          4,405,000.00          4,405,000.00  0.00          0.00        0.00          0.00           4,405,000.00           0.00

X                           221.66                3,438,489.58  0.00          936,324.40  0.00          0.00           4,374,813.98           0.00

P                           100.00                100.00        0.00          0.00        0.00          0.00           100.00                 0.00

R                           0.00                  0.00          0.00          0.00        0.00          0.00           0.00                   0.00

  Totals                    247,333,000.00        166,084,818.8813,554,945.37 399,459.62  13,554,945.37 0.00           153,466,197.91         0.00

Collateral Summary

ASSET CHARACTERISTICS

                            Cut-Off               Prior         Current

Aggregate Stated Principal
Balance                     251,738,321.66        166,084,818.88153,466,197.91

Loan Count                  6,184                 4,360         4,079

Weighted Average Coupon Rate
(WAC)                       10.522611%            10.512410%    N/A

Net Weighted Average Coupon
Rate (Net WAC)              10.172207%            10.000910%    N/A

Weighted Average Maturity
(WAM in months)             209                   204           203

AVAILABLE PRINCIPAL         AVAILABLE INTEREST

Scheduled Interest          1,454,959.34
Curtailments                33,595.26
Less:                       Servicing Fees        69,202.43
Insurance Fees              0.00
Uncompensated PPIS          0.00
Trustee Fees                1,591.47
Credit Manager Fees         2,076.06
Relief Act Shortfall        283.38
Other Interest Reductions   3,394.90
Current Realized Losses     16,931.26
TOTAL AVAILABLE INTEREST    1,378,411.10

Delinquency Information

Less Than
30 Days                     30-59 Days            60-89 Days    90+ Days      Totals

Delinquency

Scheduled Principal Balance 2,033,373.33          989,828.07    2,587,595.15  5,610,796.55
Percentage of Total Pool
Balance                     1.3250%               0.6450%       1.6861%       3.6560%
Number of Loans             56                    27            70            153

Percentage of Total Loans   1.3729%               0.6619%       1.7161%       3.7509%
Bankruptcy

Scheduled Principal Balance 1,090,400.09          89,872.11     137,444.17    515,707.01  1,833,423.38
Percentage of Total Pool
Balance                     0.7105%               0.0586%       0.0896%       0.3360%     1.1947%

Number of Loans             26                    3             3             16          48
Percentage of Total Loans   0.6374%               0.0735%       0.0735%       0.3923%     1.1768%

Foreclosure

Scheduled Principal Balance                       0.00          31,847.62     1,292,027.621,323,875.24
Percentage of Total Pool Balance                  0.0000%       0.0208%       0.8419%     0.8626%

Number of Loans                                   0             1             36          37
Percentage of Total Loans                         0.0000%       0.0245%       0.8826%     0.9071%

REO

Scheduled Principal Balance                       0.00          0.00          312,937.80  312,937.80
Percentage of Total Pool Balance                  0.0000%       0.0000%       0.2039%     0.2039%

Number of Loans                                   0             0             6           6
Percentage of Total Loans                         0.0000%       0.0000%       0.1471%     0.1471%

Total

Scheduled Principal Balance 1,090,400.09          2,123,245.44  1,159,119.86  4,708,267.589,081,032.97
Percentage of Total Pool
Balance                     0.7105%               1.3835%       0.7553%       3.0680%     5.9173%

Number of Loans             26                    59            31            128         244
Percentage of Total Loans   0.6374%               1.4464%       0.7600%       3.1380%     5.9819%

Principal and Interest
Advances                    1,226,412.36

Credit Enhancement

GROUP 1

Required Overcollateralization Amount             5,286,504.75  2.1000%
Prior Overcollateralization Amount                3,438,589.58  2.0704%
Overcollateralization
Deficiency Amount           1,847,915.17
Excess Overcollateralization
Amount                      0.00

Excess Spread Available for
O/C Deficiency              936,324.40
Overcollateralization
Increase Amount             936,324.40
Overcollateralization
Reduction Amount            0.00

Current
Overcollateralization                             4,374,913.98  1.7379%

Other Information

Additional Realized Losses
from Prior Liquidations     0.00

Class X Notional Amount     153,466,197.91

Current Libor               2.180000%
Next Libor                  2.417500%

Basis Risk Reserve Fund
Balance                     1,000.00

A1 Next Pass-Through Rate   2.547500%
A2 Next Pass-Through Rate   2.767500%
M1 Next Pass-Through Rate   2.967500%
M2 Next Pass-Through Rate   3.567500%
M3 Next Pass-Through Rate   3.917500%
M4 Next Pass-Through Rate   4.117500%
M5 Next Pass-Through Rate   5.167500%
B1 Next Pass-Through Rate   7.000000%
B2 Next Pass-Through Rate   7.000000%

CONTACT INFORMATION         CONTENTS

Distribution Summary        2
Depositor                   Structured Asset
                            Securities Corporation
Distribution Summary
(Factors)                   2

New York, NY  10019
Interest Distribution       2
Underwriter                 Lehman Brothers
745 Seventh Avenue, 7th
Floor
Principal Distribution      2
New York, NY  10019

Collateral Summary          2
2530 South Parker Road, Suite 601

Delinquency Information     2

Trustee                     Citibank, N.A.
Credit Enhancement          2

New York, NY  10013
Other Information           2

Deal Contact:               Karen Schluter        Citibank, N.A.
karen.schluter@citigroup.com                      Agency and
                                                  Trust
                                                  388 Greenwich
Tel: (212) 816-5827                               Street, 14th
                                                  Floor
Fax: (212) 816-5527                               New York, NY
                                                  10013

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                            www.sf.citidirect.com 2004 Citigroup

STRUCTURED ASSET SEC CORP MORT PASS THR CERTS SER 2004-S1 8-K