SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event

Reported): May 18, 2005

Credit Suisse First Boston Mortgage Securities Corp.
CSFB Home Equity Asset Trust 2003-4

CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIES CORP.
(Exact name of registrant as specified in its charter)
Delaware	333-107055	13-3320910
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(I.R.S. Employer Identification No.)

Eleven Madison Avenue New York, New York 10010
(Address of Principal Executive Offices) (Zip Code)

Registrant’s telephone number, including area code (212) 325-2000

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

[ ]	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
[ ]	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
[ ]	Pre-commencement communications pursuant to Rule 14d-2(d) under the Exchange Act (17 CFR 240.14d-2(b))
[ ]	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01. Other Events.

This Current Report on Form 8-K is being filed to file a copy of Amendment No. 2 to the Pooling and Servicing Agreement dated as of June 1, 2003, among Credit Suisse First Boston Mortgage Securities Corp., as depositor, DLJ Mortgage Capital, Inc., as seller, Chase Home Finance LLC, as a servicer, Ocwen Federal Bank FSB, as a servicer, The Murrayhill Company, as credit risk manager and U.S. Bank National Association, as trustee (the “Pooling and Servicing Agreement”), in connection with the issuance by Home Equity Asset Trust 2003-4 of Home Equity Pass-Through Certificates, Series 2003-4.

Item 9.01.

Financial Statements and Exhibits.

(q)

Not applicable.

(r)

Not applicable.

(s)

Exhibits:

4.1	Amendment No. 2 to the Pooling and Servicing Agreement

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

CREDIT SUISSE FIRST BOSTON MORTGAGE CORP.

By:

/s/ Kevin Steele__

Name:

Kevin Steele

Title:

Vice President

Dated: May 18, 2005

EXHIBIT 4.1

Filing Compare · CSFB HOME EQUITY PASS THROUGH CERTS SER 2003-4