UNITED STATES

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)

January 31, 2005

STRUCTURED ASSET SECURITIES CORPORATION (as Depositor under the Trust Agreement, dated as of January 1, 2005, providing for the issuance of Mortgage Pass-Through Certificates, Series 2005-1)

Structured Asset Securities Corporation

(Exact Name of Registrant as Specified in its Charter)

Delaware

333-120575

74-2440850

(State or Other Jurisdiction

Of Incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)

745 Seventh Avenue, 7^th Floor

New York, NY

10019

(Address of Principal

Executive Offices)

(Zip Code)

Registrant’s telephone number, including area code: (212) 526-7000

No Change

(Former Name or Former Address, if Changed Since Last Report)

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(b) 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

The Registrant registered issuances of Mortgage Pass-Through Certificates, on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended (the “Act”), by a Registration Statement on Form S-3 (Registration File No. 333-120575) (the “Registration Statement”). Pursuant to the Registration Statement, the Registrant issued $1,288,823,867 in aggregate principal amount of Class 1-A1, Class 1-A2, Class 1-A3, Class 1-A4, Class 1-A5, Class 1-A6, Class 2-A1, Class 3-A1, Class 4-A1, Class 5-A1, Class 6-A1, Class 7-A1, Class 7-A2, Class 7-A3, Class 7-A4, Class 7-A5, Class 7-A6, Class 7-A7, Class AP, Class AX, Class B1, Class B2, Class B3 and Class R Structured Asset Securities Corporation Mortgage Pass-Through Certificates, Series 2005-1 on January 31, 2005. This Current Report on Form 8-K is being filed to satisfy an undertaking, contained in the definitive Prospectus dated January 25, 2005, as supplemented by the Prospectus Supplement dated January 26, 2005 (collectively, the “Prospectus”), to file a copy of the Trust Agreement (as defined below) and other operative agreements executed in connection with the issuance of the Certificates, a form of which was filed as an exhibit to the Registration Statement.

The Certificates were issued pursuant to a trust agreement (the “Trust Agreement”), attached hereto as Exhibit 4.1, dated as of January 1, 2005, among Structured Asset Securities Corporation, as depositor, Citibank, N.A., as trustee, and Aurora Loan Services LLC, as master servicer. The “Certificates” consist of the following classes: Class 1-A1, Class 1-A2, Class 1-A3, Class 1-A4, Class 1-A5, Class 1-A6, Class 2-A1, Class 3-A1, Class 4-A1, Class 5-A1, Class 6-A1, Class 7-A1, Class 7-A2, Class 7-A3, Class 7-A4, Class 7-A5, Class 7-A6, Class 7-A7, Class AP, Class AX, Class B1, Class B2, Class B3, Class B4, Class B5, Class B6, Class B7, Class P and Class R.

The Certificates evidence all of the beneficial ownership interest in a trust fund (the “Trust Fund”) the assets of which consist primarily of seven pools of certain fixed rate, conventional, fully amortizing, first lien, residential mortgage loans (the “Mortgage Loans”) with an aggregate outstanding principal balance of approximately $1,299,875,209 as of January 1, 2005, together with certain other assets. Capitalized terms used herein and not otherwise defined shall have the meanings assigned to them in the Trust Agreement.

Item 9.01. Financial Statements; Pro Forma Financial Information and Exhibits

(a)

Not applicable.

(b)

Not applicable.

(c)

Exhibits:

4.1

Trust Agreement dated as of January 1, 2005, among Structured Asset Securities Corporation, as Depositor, Citibank, N.A., as Trustee, and Aurora Loan Services LLC, as Master Servicer.

99.1

Mortgage Loan Sale and Assignment Agreement dated as of January 1, 2005, between Lehman Brothers Holdings Inc., as Seller, and Structured Asset Securities Corporation, as Purchaser.

99.2

Servicing Agreement, dated as of January 1, 2005, among Aurora Loan Services LLC, as Master Servicer and Servicer, and Lehman Brothers Holdings Inc., as Seller.

SIGNATURES

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

STRUCTURED ASSET SECURITIES

CORPORATION

By: /s/ Ellen V. Kiernan

Name: Ellen V. Kiernan

Title: Senior Vice President

Dated: January 31, 2005

EXHIBIT INDEX

Exhibit No.

Description

4.1

Trust Agreement dated as of January 1, 2005, among Structured Asset Securities Corporation, as Depositor, Citibank, N.A., as Trustee, and Aurora Loan Services LLC, as Master Servicer.

99.1

Mortgage Loan Sale and Assignment Agreement dated as of January 1, 2005, between Lehman Brothers Holdings Inc., as Seller, and Structured Asset Securities Corporation, as Purchaser.

99.2

Servicing Agreement, dated as of January 1, 2005, among Aurora Loan Services LLC, as Master Servicer and Servicer, and Lehman Brothers Holdings Inc., as Seller.

Structured Asset Securities Corp Mortgage Pass-Through Certificates, Series 2005-1 8-K