Fitch Rates Chase Mortgage Finance Trust 2007-S1.

NEW YORK -- Chase Mortgage Finance Trust, series 2007-S1 is rated by Fitch as follows:

--$409,839,967 classes A-1 through A-13, A-X, A-P, and A-R (senior certificates) 'AAA';

--$7,529,800 class A-M, 'AA+';

--$6,884,500 class M-1, 'AA';

--$2,366,500 class B-1, 'A';

--$1,506,000 class B-2, 'BBB';

--$860,500 privately offered B-3, 'BB';

--$430,300 privately offered B-4, 'B'.

The 'AAA' rating on the senior classes reflects the 4.75% subordination provided by the 1.75% class A-M, the 1.60% class M-1, the 0.55% class B-1, the 0.35% class B-2, the 0.2% privately offered class B-3, the 0.10% privately offered class B-4 and the 0.2% privately offered and not rated class B-5 certificates.

Fitch believes the above credit enhancement will be adequate to support mortgagor defaults as well as bankruptcy, fraud and special hazard losses in limited amounts. In addition, the ratings also reflect the quality of the underlying mortgage collateral, strength of the legal and financial structures, and the primary servicing capabilities of JPMorgan Chase Bank, N.A. (rated 'RPS1' by Fitch).

This transaction contains certain classes designated as exchangeable certificates and others as regular certificates. Class A-7 and A-13 are exchangeable certificates. Classes A-1 through A-6, A-8 through A-12, A-X, A-P, A-R, A-M, M-1, and B-1 through B-5 are regular certificates.

The holder of the Exchangeable Initial Certificates in any Exchangeable Combination may exchange all or part of each class of such Exchangeable Initial Certificates for a proportionate interest in the related Exchangeable Certificates. The holder of any class of Exchangeable Certificates may exchange all or part of such class for a proportionate interest in each such class of Exchangeable Initial Certificates or for other Exchangeable Certificates in the related Exchangeable Combination.

The classes of Exchangeable Initial Certificates and Exchangeable Certificates that are outstanding on any date and the outstanding principal balances (or notional amounts, as applicable) of any such classes will depend upon the aggregate distributions of principal made to such classes, as well as any exchanges that may have occurred on or prior to such date. For the purposes of the exchanges and the calculation of the principal balance of any class of Exchangeable Initial Certificates, to the extent that exchanges of Exchangeable Initial Certificates for Exchangeable Certificates occur, the aggregate principal balance of the Exchangeable Initial Certificates will be deemed to include the principal balance (or notional amount, as applicable) of such Exchangeable Certificates issued in the exchange, and the principal balance (or notional amount, as applicable) of such Exchangeable Certificates will be deemed to be zero. Exchangeable Initial Certificates in any Exchangeable Combination and the related Exchangeable Certificates may be exchanged only in the specified proportion that the original principal balances (or notional amounts, as applicable) of such certificates bear to one another.

Any holders of Exchangeable Certificates will be the beneficial owners of an interest in the Exchangeable Initial Certificates in the related Exchangeable Combination and will receive a proportionate share, in the aggregate, of the aggregate distributions on those certificates. With respect to any Distribution Date, the aggregate amount of principal and interest distributable to any classes of Exchangeable Certificates and the Exchangeable Initial Certificates in the related Exchangeable Combination then outstanding on such Distribution Date will be equal to the aggregate amount of principal and interest otherwise distributable to all of the Exchangeable Initial Certificates in the related Exchangeable Combination on such Distribution Date as if no Exchangeable Certificates were then outstanding.

The trust consists of 703 first-lien residential mortgage loans with stated maturity of not more than 30 years with an aggregate principal balance of $430,278,182 as of the cut-off date, Jan. 1, 2007. The mortgage pool has a weighted average original loan-to-value ratio of 73.21% with a weighted average mortgage rate of 6.528%. The weighted-average FICO score of the loans is 744. The average loan balance is $612,060 and the loans are primarily concentrated in California (30.9%), New York (17.7%) and Florida (10.6%).

None of the mortgage loans are 'high cost' loans as defined under any local, state or federal laws. For additional information on Fitch's rating criteria regarding predatory lending legislation, please see the press release issued May 1, 2003 entitled 'Fitch Revises Rating Criteria in Wake of Predatory Lending Legislation', available on the Fitch Ratings web site at www.fitchratings.com.

The Bank of New York Trust Company, N.A will serve as trustee. Chase Mortgage Finance Corporation, a special purpose corporation, deposited the loans in the trust which issued the certificates. For federal income tax purposes, an election will be made to treat the trust fund as one or more real estate mortgage investment conduits (REMICs).

Fitch's rating definitions and the terms of use of such ratings are available on the agency's public site, www.fitchratings.com. Published ratings, criteria and methodologies are available from this site, at all times. Fitch's code of conduct, confidentiality, conflicts of interest, affiliate firewall, compliance and other relevant policies and procedures are also available from the 'Code of Conduct section of this site.