Preview | Underwriting Agreement |

Option One Mortgage Acceptance Corporation (the Depositor), a Delaware corporation, has authorized the issuance and sale of Option One Mortgage Loan Trust, Series 2007-CP1, Class I-A-1 Certificates, Class II-A-1 Certificates, Class II-A-2 Certificates, Class II-A-3 Certificates, Class M-1 Certificates, Class M-2 Certificates, Class M-3 Certificates, Class M-4 Certificates, Class M-5 Certificates, Class M-6 Certificates, Class M-7 Certificates, Class M-8 Certificates and Class M-9 Certificates (collectively, the Underwritten Certificates). Also issued are the Class C Certificates, Class P Certificates, Class R Certificates and Class R-X Certificates (collectively, the Non-Offered Certificates). The Underwritten Certificates and the Non-Offered Certificates are referred to as the Certificates (the Certificates).

The Certificates will evidence fractional undivided interests in the Trust (the Trust) formed pursuant to the Pooling and Servicing Agreement. The assets of the Trust will include, among other things, a pool of adjustable-rate mortgage loans (collectively, the Mortgage Loans), the Net WAC Rate Carryover Reserve Account and the Swap Account (including any payments made under the Swap Administration Agreement deposited in the Trust) and such amounts as may be held by the Trustee in any other accounts held by the Trustee for the Trust. First deeds of trust or mortgages on one- to four-family residential properties secure the Mortgage Loans. A form of the Pooling and Servicing Agreement has been filed as an exhibit to the Registration Statement.

Pursuant to the Mortgage Loan Purchase Agreement, dated February 15, 2007 (the Mortgage Loan Purchase Agreement), among Option One Mortgage Corporation (Option One), Option One Mortgage Capital Corporation, Option One Owner Trust 2001-1A, Option One Owner Trust 2001-1B, Option One Owner Trust 2001-2, Option One Owner Trust 2002-3, Option One Owner Trust 2003-4, Option One Owner Trust 2003-5, Option One Owner Trust 2005-6, Option One Owner Trust 2005-7, Option One Owner Trust 2005-8 and Option One Owner Trust 2005-9 as sellers (and together with Option One and Option One Mortgage Capital Corporation, the Sellers) and the Depositor, the Sellers will transfer to the Depositor all of their right, title and interest in and to the scheduled principal balances of the Mortgage Loans as of the Cut-off Date and interest due after the Cut-off Date and the collateral securing each Mortgage Loan. Pursuant to the Pooling and Servicing Agreement, the Depositor will transfer to the Trust all of its right, title and interest in and to the scheduled principal balances of the Mortgage Loans as of the Cut-off Date and interest due after the Cut-off Date and the collateral securing each Mortgage Loan.

(a) A Registration Statement on Form S-3 (No. 333-130870), has (i) been prepared by the Depositor in conformity with the requirements of the Securities Act of 1933, as amended (the Securities Act) and the rules and regulations (the Rules and Regulations) of the United States Securities and Exchange Commission (the Commission) thereunder, (ii) been filed with the Commission under the Securities Act and (iii) become effective and is still effective as of the date hereof under the Securities Act. Copies of such Registration Statement have been delivered by the Depositor to the Underwriters. As used in this Agreement, Effective Time means the date and the time as of which such Registration Statement, or the most recent post-effective amendment thereto, if any, was declared effective by the Commission; Effective Date means the date of the Effective Time; Registration Statement means such registration statement, at the Effective Time, including any documents incorporated by reference therein at such time; Base Prospectus means such final prospectus dated April 3, 2006 and Prospectus Supplement means the final prospectus supplement dated the date of this Agreement relating to the Underwritten Certificates, to be filed with the Commission pursuant to paragraphs (2), (3) or (5) of Rule 424(b) of the Rules and Regulations. Prospectus means the Base Prospectus together with the Prospectus Supplement. The Depositor further proposes to prepare, after the final terms of all classes of the Underwritten Certificates are established, a Free Writing Prospectus that contains substantially all information that will appear in the Prospectus Supplement, to the extent that such information is known at that time (such Free Writing Prospectus, together with the Base Prospectus, the Preliminary Prospectus). Reference made herein to the Prospectus shall be deemed to refer to and include any documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act, as of the date of the Prospectus and any reference to any amendment or supplement to the Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any document filed under the Securities Exchange Act of 1934 (the Exchange Act) after the date of the Preliminary Prospectus or the Prospectus, as applicable, and incorporated by reference in the Preliminary Prospectus or the Prospectus, as applicable, and any reference to any amendment to the Registration Statement shall be deemed to include any report of the Depositor filed with the Commission pursuant to Section 13(a) or 15(d) of the Exchange Act after the Effective Time that is incorporated by reference in the Registration Statement.

The Commission has not issued any order preventing or suspending the use of the Prospectus or the Preliminary Prospectus or the effectiveness of the Registration Statement and no proceedings for such purpose are pending or, to the Depositor's knowledge, threatened by the Commission. There are no contracts or documents of the Depositor which are required to be filed as exhibits to the Registration Statement pursuant to the Securities Act or the Rules and Regulations which have not been so filed or incorporated by reference therein on or prior to the Effective Date of the Registration Statement other than such documents or materials, if any, as any Underwriter delivers to the Depositor pursuant to Section 5(b) hereof for filing on Form 8-K. The conditions for use of Form S-3, as set forth in the General Instructions thereto, have been satisfied.

(b) The Registration Statement, the Preliminary Prospectus and the Prospectus conform, and any further amendments or supplements to the Registration Statement, the Preliminary Prospectus or the Prospectus will conform, when they become effective, are filed with the Commission or as of the date of the Contract of Sale, as the case may be, in all respects to the requirements of the Securities Act and the Rules and Regulations. The Registration Statement, as of the Effective Date thereof and of any amendment thereto, did not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. The Preliminary Prospectus, as amended or supplemented as of its date or as of the date of the Contract of Sale, and the Prospectus as of its date, and as amended or supplemented as of the Closing Date does not and will not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading; provided that no representation or warranty is made as to information contained in or omitted from the Registration Statement, the Preliminary Prospectus or the Prospectus in reliance upon and in conformity with written information furnished to the Depositor in writing by the Underwriters expressly for use therein which shall be limited to the highlighted information set forth on Exhibit A hereto (the Underwriters' Information) or any Derived Information.

Greenwich Capital Markets, Inc. 600 Steamboat Road Greenwich, Connecticut 06830	Banc of America Securities LLC 214 North Tryon Street Charlotte, North Carolina 28255

Citigroup Global Markets Inc. 390 Greenwich Street New York, New York 10005	H&R Block Financial Advisors Inc. 719 Griswold Street Detroit, Michigan 48226

HSBC Securities (USA) Inc. 452 Fifth Avenue New York, New York 10018	J.P. Morgan Securities Inc. 270 Park Avenue New York, New York 10017