UNITED STATES
                     SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549

                                  FORM 10-K


  (Mark one)

  /X/ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
      EXCHANGE ACT OF 1934
      For the fiscal year ended December 31, 2007

      OR


  / / TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
      EXCHANGE ACT OF 1934
      For the transition period from ____________ to ____________



      Commission file number: 333-141607-11

      J.P. Morgan Mortgage Trust 2007-S3
      (exact name of issuing entity as specified in its charter)

      J.P. Morgan Acceptance Corporation I
      (exact name of the depositor as specified in its charter)

      J.P. Morgan Mortgage Acquisition Corp.
      (exact name of the sponsor as specified in its charter)



  Delaware                                13-3475488
  (State or other jurisdiction of         (I.R.S. Employer
  incorporation or organization)          Identification No.)



  270 Park Avenue
   New York, NY                                10017
  (Address of principal executive             (Zip Code)
  offices)


 Telephone number, including area code: (212) 648-0364



  Securities registered pursuant to Section 12(b) of the Act:

    NONE.



  Securities registered pursuant to Section 12(g) of the Act:

    NONE.



  Indicate by check mark if the registrant is a well-known seasoned issuer, as
  defined in Rule 405 of the Securities Act.

    Yes ___     No  X



  Indicate by check mark if the registrant is not required to file reports
  pursuant to Section 13 or Section 15(d) of the Act.

    Yes ___     No  X




  Indicate by check mark whether the registrant (1) has filed all reports
  required to be filed by Section 13 or 15(d) of the Securities Exchange Act
  of 1934 during the preceding 12 months (or for such shorter period that the
  registrant was required to file such reports), and (2) has been subject to
  such filing requirements for the past 90 days.

    Yes  X      No ___



  Indicate by check mark if disclosure of delinquent filers pursuant to Item
  405 of Regulation S-K (Section 229.405 of this chapter) is not contained
  herein, and will not be contained, to the best of registrant's knowledge, in
  definitive proxy or information statements incorporated by reference in Part
  III of this Form 10-K or any amendment to this Form 10-K.

    Not applicable.



  Indicate by check mark whether the registrant is a large accelerated filer,
  an accelerated filer, a non-accelerated filer, or a smaller reporting
  company.  See the definitions of "large accelerated filer", "accelerated
  filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

   Large accelerated filer ___
   Accelerated filer ___
   Non-accelerated filer X
   Smaller reporting company ___

  Indicate by check mark whether the registrant is a shell company (as defined
  in Rule 12b-2 of the Act).

    Yes ___     No  X



  State the aggregate market value of the voting and non-voting common equity
  held by non-affiliates computed by reference to the price at which the
  common equity was last sold, or the average bid and asked price of such
  common equity, as of the last business day of the registrant's most recently
  completed second fiscal quarter.

    Not applicable.



  Indicate by check mark whether the registrant has filed all documents and
  reports required to be filed by Section 12, 13 or 15(d) of the Securities
  Exchange Act of 1934 subsequent to the distribution of securities under a
  plan confirmed by a court.

    Not applicable.



  Indicate the number of shares outstanding of each of the registrant's
  classes of common stock, as of the latest practicable date.

    Not applicable.



  DOCUMENTS INCORPORATED BY REFERENCE

  List hereunder the following documents if incorporated by reference and the
  Part of the Form 10-K (e.g., Part I, Part II, etc.) into which the document
  is incorporated: (1)Any annual report to security holders; (2) Any proxy or
  information statement; and (3)Any prospectus filed pursuant to Rule 424(b)
  or (c) under the Securities Act of 1933. The listed documents should be
  clearly described for identification purposes (e.g., annual report to
  security holders for fiscal year ended December 24, 1980).

    Not applicable.





                                     PART I

  Item 1.      Business.

               Omitted.


  Item 1A.     Risk Factors.

               Omitted.


  Item 1B.     Unresolved Staff Comments.

               None.


  Item 2.      Properties.

               Omitted.


  Item 3.      Legal Proceedings.

               Omitted.


  Item 4.      Submission of Matters to a Vote of Security Holders.

               Omitted.




                                     PART II

  Item 5.      Market for Registrant's Common Equity, Related Stockholder
               Matters and Issuer Purchases of Equity Securities.

               Omitted.


  Item 6.      Selected Financial Data.

               Omitted.


  Item 7.      Management's Discussion and Analysis of Financial Condition and
               Results of Operation.

               Omitted.


  Item 7A.     Quantitative and Qualitative Disclosures About Market Risk.

               Omitted.


  Item 8.      Financial Statements and Supplementary Data.

               Omitted.


  Item 9.      Changes in and Disagreements With Accountants on Accounting and
               Financial Disclosure.

               Omitted.


  Item 9A.     Controls and Procedures.

               Omitted.


  Item 9A(T).  Controls and Procedures.

               Omitted.


  Item 9B.     Other Information.

               None.




                                    PART III

  Item 10.     Directors, Executive Officers and Corporate Governance.

               Omitted.


  Item 11.     Executive Compensation.

               Omitted.


  Item 12.     Security Ownership of Certain Beneficial Owners and Management
               and Related Stockholder Matters.

               Omitted.


  Item 13.     Certain Relationships and Related Transactions, and Director
               Independence.

               Omitted.


  Item 14.     Principal Accounting Fees and Services.

               Omitted.




  ADDITIONAL DISCLOSURE ITEMS FOR REGULATION AB


Item 1112(b) of Regulation AB, Significant Obligor Financial Information.

No single obligor represents 10% or more of the pool assets held by the issuing
entity.



Item 1114(b)(2) of Regulation AB, Significant Enhancement  Provider Financial
Information.

No entity or group of affiliated entities provides any external credit
enhancement or other support for the certificates within this transaction as
described under Item 1114 (a) of Regulation AB.



Item 1115(b) of Regulation AB, Certain Derivatives Instruments (Financial
Information).

JPMorgan Chase Bank, National Association provides a yield maintenance
agreement derivative instrument for the trust as disclosed in the 424(b)(5)
filing dated July 31, 2007, Commission File Number 333-141607-11, CIK Number
0001406911. No additional disclosure is necessary because the significance
percentage for the yield maintenance agreement is less than 10%.



Item 1117 of Regulation AB, Legal Proceedings.

As disclosed by American Home Mortgage Investment Corp. ("American Home
Mortgage") in its Current Report on Form 8-K (Commission File Number 001-31916,
CIK Number 0001256536) filed with the U.S. Securities and Exchange Commission
(the "SEC") on August 9, 2007, on August 6, 2007, American Home Mortgage issued
a press release announcing that American Home Mortgage, together with certain
of its subsidiaries, including American Home Mortgage Servicing, Inc. ("AHM
Servicing"), had filed a voluntary petition for relief under Chapter 11 of the
U.S. Bankruptcy Code in the U.S. Bankruptcy Court for the District of Delaware
(the "Bankruptcy Court") (American Home Mortgage Holdings, Inc., a Delaware
corporation, et al. Case No. 07-11047(CSS)).

As disclosed by American Home Mortgage in its Current Report on Form 8-K
(Commission File Number 001-31916, CIK Number 0001256536) filed with the SEC on
September 28, 2007, on September 25, 2007, American Home Mortgage and its
subsidiaries, American Home Mortgage Corp. and AHM Servicing entered into an
Asset Purchase Agreement with AH Mortgage Acquisition Co., Inc., an entity
newly formed by WL Ross & Company, LLC, for the sale of American Home
Mortgage's mortgage servicing assets and mortgage servicing platform for a
purchase price to be determined by a formula based on mortgage servicing rights
and advances outstanding at the time of closing on the transaction. By Order
dated October 30, 2007, the Bankruptcy Court approved and authorized that sale.

On March 26, 2008, the depositor was served with a class action lawsuit filed
by Plumbers' & Pipefitters' Local #562 Supplemental Plan & Trust and Plumbers'
& Pipefitters' Local #562 Pension Fund before the Supreme Court of the State of
New York. The suit involves claims under section 11 of the Securities Act of
1933 for alleged false and misleading registration statements and prospectus
supplements filed with the Commission between January 2006 and March 2007.



Item 1119 of Regulation AB, Affiliations and Certain Relationships and Related
Transactions.

The information regarding this Item has been previously filed in a 424(b)(5)
filing dated July 31, 2007, Commission File Number 333-141607-11, CIK Number
0001406911.



Item 1122 of Regulation AB, Compliance with Applicable Servicing Criteria.

The reports on assessment of compliance with the servicing criteria for
asset-backed securities and the related attestation reports on such assessments
of compliance are attached hereto under Item 15.

The following parties have reported one or more instances of material
noncompliance with applicable servicing criteria in their reports on
assessments of compliance:

The assessment of compliance for American Home Mortgage Servicing, Inc.
disclosed the following material noncompliance with servicing criteria
1122(d)(2)(i) and 1122(d)(4)(iii), as applicable during the twelve months
ended December 31, 2007:

* With respect to servicing criterion 1122(d)(2)(i), certain obligor
  remittances were not deposited into the appropriate custodial bank accounts
  within two business days of receipt as required by the related transaction
  agreements. Payments on pool assets were not deposited into the appropriate
  custodial bank accounts within two business days of receipt as specified in
  the transaction documents for various securitizations serviced by American
  Home Mortgage Servicing, Inc. as a result of a unilateral bank decision by
  JPMorgan Chase Bank, N.A., the depository bank, to require a fully funded
  daily payment clearing bank account (called a "prefund status") between
  August 1, 2007 and December 20, 2007. This requirement added one day of delay
  to the funds transfer process during that period. American Home Mortgage
  Servicing, Inc. believes it is in compliance with the requirements of
  servicing criterion 1122(d)(2)(i) as of December 20, 2007.

* With respect to servicing criterion 1122(d)(4)(iii), certain removals from
  the asset pool were not made within the timeframe required by the related
  transaction agreements. For one of the 75 securitizations American Home
  Mortgage Servicing, Inc. serviced during 2007, the pooling and servicing
  agreement restricted American Home Mortgage Servicing, Inc.'s ability to
  comply with that document while acting in the best interests of the trust. In
  particular, the pooling and servicing agreement for the transaction provided
  that American Home Mortgage Servicing, Inc. was required to charge-off any
  loans in the trust that were delinquent for 180 days, but did not provide for
  the simultaneous transfer of such loans to the depositor (or its designee).
  In January 2008, the pooling and servicing agreement for the transaction was
  amended to provide for such simultaneous transfer.

Although each servicing criterion required by Item 1122(d) of Regulation AB is
addressed in one or more of the Assessments of Compliance with Servicing
Criteria and related Attestation Reports included with this report, the
Assessment of Compliance of American Home Mortgage Servicing, Inc. (the
"Servicer") and related Attestation Report did not address each of the
servicing criteria that the Servicer was required to address under the terms of
the related Servicing Agreement. The Servicer has not identified such failure
to provide an Assessment and Attestation for these items as a material failure
to fulfill its obligations under the related servicing agreement in the
Servicer Compliance Statement provided under Item 1123 of Regulation AB,
because the Servicer asserts that those items are not applicable to the
Servicer.



Item 1123 of Regulation AB, Servicer Compliance Statement.

The servicer compliance statements are attached hereto under Item 15.



                               Part IV

  Item 15. Exhibits, Financial Statement Schedules.

  (a) Exhibits.

  (4) Instruments defining the rights of security holders.

  4.1 Pooling and Servicing Agreement (filed as an exhibit to Form 8-K/A
  on September 5, 2007, Commission File Number 333-141607-11, CIK
  Number 0001406911, and incorporated by reference herein).

  4.2 Trust Agreement (filed as an exhibit to Form 8-K/A on March 25,
  2008, Commission File Number 333-141607-11, CIK Number 0001406911,
  and incorporated by reference herein).

  (10) Incorporated by reference as Exhibit (4).

  (31) Rule 13a-14(d)/15d-14(d) Certification.

  (33) Reports on assessment of compliance with servicing criteria for
  asset-backed securities.


    <TABLE>
    
      <c>

    33.1 American Home Mortgage Servicing, Inc. as Servicer
    33.2 Chase Home Finance LLC as Sub-Servicer for JPMorgan Chase Bank, N.A.
    33.3 JPMorgan Chase Bank, N.A. as Named Servicer
    33.4 JPMorgan Chase Bank, N.A. as Custodian
    33.5 The Bank of New York Trust Company, National Association as Custodian
    33.6 Wells Fargo Bank, N.A. as Master Servicer and Securities Administrator
    33.7 Wells Fargo Bank, N.A. as Paying Agent

    </TABLE>


  (34) Attestation reports on assessment of compliance with servicing criteria
  for asset-backed securities.


    <TABLE>
    
      <c>

    34.1 American Home Mortgage Servicing, Inc. as Servicer
    34.2 Chase Home Finance LLC as Sub-Servicer for JPMorgan Chase Bank, N.A.
    34.3 JPMorgan Chase Bank, N.A. as Named Servicer
    34.4 JPMorgan Chase Bank, N.A. as Custodian
    34.5 The Bank of New York Trust Company, National Association as Custodian
    34.6 Wells Fargo Bank, N.A. as Master Servicer and Securities Administrator
    34.7 Wells Fargo Bank, N.A. as Paying Agent

    </TABLE>


   (35) Servicer compliance statement.


    <TABLE>
    
       <c>

    35.1 American Home Mortgage Servicing, Inc. as Servicer
    35.2 Chase Home Finance LLC as Sub-Servicer for JPMorgan Chase Bank, N.A.
    35.3 JPMorgan Chase Bank, N.A. as Named Servicer
    35.4 Wells Fargo Bank, N.A. as Master Servicer and Securities Administrator

    </TABLE>


   (b) Exhibits identified in paragraph (a) above.

   (c) Omitted.



                          SIGNATURES


  Pursuant to the requirements of Section 13 or 15(d) 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.


   J.P. Morgan Mortgage Trust 2007-S3
   (Issuing Entity)

   /s/ Christina Hatfield
   Christina Hatfield, Vice President
   (senior officer in charge of the servicing function of the master
   servicer)

   Wells Fargo Bank, N.A.
   (Master Servicer)


    Date:   March 28, 2008



  Exhibit Index

  Exhibit No.


   (4) Instruments defining the rights of security holders.

   4.1 Pooling and Servicing Agreement (filed as an exhibit to Form 8-K/A
   on September 5, 2007, Commission File Number 333-141607-11, CIK
   Number 0001406911, and incorporated by reference herein).

   4.2 Trust Agreement (filed as an exhibit to Form 8-K/A on March 25,
   2008, Commission File Number 333-141607-11, CIK Number 0001406911,
   and incorporated by reference herein).

   (10) Incorporated by reference as Exhibit (4).

   (31) Rule 13a-14(d)/15d-14(d) Certification.

   (33) Reports on assessment of compliance with servicing criteria for
   asset-backed securities.


    <TABLE>

    
      <c>
    33.1 American Home Mortgage Servicing, Inc. as Servicer
    33.2 Chase Home Finance LLC as Sub-Servicer for JPMorgan Chase Bank, N.A.
    33.3 JPMorgan Chase Bank, N.A. as Named Servicer
    33.4 JPMorgan Chase Bank, N.A. as Custodian
    33.5 The Bank of New York Trust Company, National Association as Custodian
    33.6 Wells Fargo Bank, N.A. as Master Servicer and Securities Administrator
    33.7 Wells Fargo Bank, N.A. as Paying Agent

    </TABLE>

   (34) Attestation reports on assessment of compliance with servicing
   criteria for asset-backed securities.


    <TABLE>

    
      <c>
    34.1 American Home Mortgage Servicing, Inc. as Servicer
    34.2 Chase Home Finance LLC as Sub-Servicer for JPMorgan Chase Bank, N.A.
    34.3 JPMorgan Chase Bank, N.A. as Named Servicer
    34.4 JPMorgan Chase Bank, N.A. as Custodian
    34.5 The Bank of New York Trust Company, National Association as Custodian
    34.6 Wells Fargo Bank, N.A. as Master Servicer and Securities Administrator
    34.7 Wells Fargo Bank, N.A. as Paying Agent

    </TABLE>

   (35) Servicer compliance statement.


    <TABLE>

    
       <c>
    35.1 American Home Mortgage Servicing, Inc. as Servicer
    35.2 Chase Home Finance LLC as Sub-Servicer for JPMorgan Chase Bank, N.A.
    35.3 JPMorgan Chase Bank, N.A. as Named Servicer
    35.4 Wells Fargo Bank, N.A. as Master Servicer and Securities Administrator

    </TABLE>