UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, DC 20549
                             --------------------

                                   FORM 10-K
                                 ANNUAL REPORT
                       PURSUANT TO SECTIONS 13 OR 15(d)
                    OF THE SECURITIES EXCHANGE ACT OF 1934

(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 of Issuing Entity: 333-140958-19
                                                      -------------

                   CHL Mortgage Pass-Through Trust 2007-HY4,
              Mortgage Pass-Through Certificates, Series 2007-HY4
              ---------------------------------------------------
          (Exact name of Issuing Entity as Specified in Its Charter)

                Commission file number of Depositor: 333-140958
                                                     ----------

                                  CWMBS, Inc.
                                  -----------
             (Exact name of Depositor as Specified in Its Charter)

                         Countrywide Home Loans, Inc.
                         ----------------------------
              (Exact name of Sponsor as Specified in Its Charter)

              Delaware                                   95-4449516
------------------------------------           -------------------------------
(State or Other Jurisdiction of                (I.R.S. Employer Identification
Incorporation or Organization of               No. of the Depositor)
the Depositor)

c/o  Countrywide Home Loans Servicing LP
     4500 Park Granada
     Calabasas, California                                  91302
----------------------------------------       -------------------------------
(Address of Principal Executive Offices                  (Zip Code)
of the Depositor)

Registrant's telephone number, including area code:   (818) 225-3000
                                                      --------------

Securities registered pursuant to Section 12(b) of the Act:  None
                                                             ----

Securities registered pursuant to Section 12(g) of the Act:  None
                                                             ----


<PAGE>


      Indicate by check mark if the registrant is a well-known seasoned
issuer, as defined in Rule 405 of the Securities Act.           [_] Yes [X] No

      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 [X] No

      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.                  [X] Yes [_] No

      Indicate by check mark if disclosure of delinquent filers pursuant to
Item 405 of Regulation S-K (ss.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.       [X]

      Indicate by check mark whether the registrant is a large accelerated
filer, an accelerated filer, or a non-accelerated filer. See definition of
"accelerated filer and large accelerated filer" in Rule 12b-2 of the Exchange
Act. (Check one):

Large Accelerated Filer [_]   Accelerated Filer [_]    Non-Accelerated Filer [X]

      Indicate by check mark whether the registrant is a shell company (as
defined in Rule 12b-2 of the Exchange Act).                     [_] Yes [X] No

      The Registrant has no voting or non-voting common equity held by
non-affiliates.


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<PAGE>


                      DOCUMENTS INCORPORATED BY REFERENCE

                                     None.

                                     * * *


         This Annual Report on Form 10-K (the "Report") is filed with respect
to the trust entitled CHL Mortgage Pass-Through Trust 2007-HY4 (the "Issuing
Entity") formed pursuant to the pooling and servicing agreement dated as of
September 1, 2007 (the "Pooling and Servicing Agreement") among CWMBS, Inc.,
as depositor (the "Company"), Countrywide Home Loans, Inc., as sponsor and as
a seller (the "Sponsor" and a "Seller"), Park Granada LLC, as a seller (a
"Seller"), Park Sienna LLC, as a seller (a "Seller"), Park Monaco Inc., as a
seller (a "Seller"), Countrywide Home Loans Servicing LP, as master servicer
(the "Master Servicer"), and The Bank of New York, as trustee (the "Trustee"),
for the issuance of Mortgage Pass-Through Certificates, Series 2007-HY4 (the
"Certificates").


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<PAGE>


                                    PART I


Item 1.           Business.

                  Omitted as permitted by Instruction J to Form 10-K.

Item 1A.          Risk Factors.

                  Omitted as permitted by Instruction J to Form 10-K.

Item 1B.          Unresolved Staff Comments.

                  Not Applicable.

Item 2.           Properties.

                  Omitted as permitted by Instruction J to Form 10-K.

Item 3.           Legal Proceedings.

                  Omitted as permitted by Instruction J to Form 10-K.

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

                  Omitted as permitted by Instruction J to Form 10-K.


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<PAGE>


                                    PART II


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

                  Omitted as permitted by Instruction J to Form 10-K.

Item 6.           Selected Financial Data.

                  Omitted as permitted by Instruction J to Form 10-K.

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

                  Omitted as permitted by Instruction J to Form 10-K.

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

                  Omitted as permitted by Instruction J to Form 10-K.

Item 8.           Financial Statements and Supplementary Data.

                  Omitted as permitted by Instruction J to Form 10-K.

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

                  Omitted as permitted by Instruction J to Form 10-K.

Item 9A.          Controls and Procedures.

                  Omitted as permitted by Instruction J to Form 10-K.

Item 9B.          Other Information.

                  None.


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<PAGE>


                                   PART III


Item 10.          Directors, Executive Officers and Corporate Governance.

                  Omitted as permitted by Instruction J to Form 10-K.

Item 11.          Executive Compensation.

                  Omitted as permitted by Instruction J to Form 10-K.

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

                  Omitted as permitted by Instruction J to Form 10-K.

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

                  Omitted as permitted by Instruction J to Form 10-K.

Item 14.          Principal Accountant Fees and Services.

                  Omitted as permitted by Instruction J to Form 10-K.


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<PAGE>


                                    PART IV


Item 15.          Exhibits and Financial Statement Schedules.

                  (a)   (1)    Not applicable.

                        (2)    Not applicable.

                        (3)    The required exhibits are as follows:

                               o    Exhibit 3(i): Copy of Company's
                                    Certificate of Incorporation (Filed as
                                    Exhibit 3.1 to Registration Statement on
                                    Form S-3 (File No. 33-63714))

                               o    Exhibit 3(ii): Copy of Company's By-laws
                                    (Filed as Exhibit 3.2 to Registration
                                    Statement on Form S-3 (File No. 33-63714))

                               o    Exhibit 4: Pooling and Servicing Agreement
                                    (Filed as part of the Current Report on
                                    Form 8-K filed on October 10, 2007 under
                                    the Commission file number of the Issuing
                                    Entity)

                               o    Exhibit 31(ii): Rule 15d-14(d)
                                    Certification

                               o    Exhibit 33.1: Report on Assessment of
                                    Compliance With Servicing Criteria for
                                    Asset-Backed Securities for Countrywide
                                    Financial Corporation

                               o    Exhibit 33.2: Report on Assessment of
                                    Compliance With Servicing Criteria for
                                    Asset-Backed Securities for the Trustee

                               o    Exhibit 34.1: Attestation Report on
                                    Assessment of Compliance With Servicing
                                    Criteria for Asset-Backed Securities of
                                    KPMG LLP on behalf of Countrywide
                                    Financial Corporation

                               o    Exhibit 34.2: Attestation Report on
                                    Assessment of Compliance With
                                    Servicing Criteria for Asset-Backed
                                    Securities of KPMG LLP on behalf of
                                    the Trustee

                               o    Exhibit 35: Servicer Compliance Statement
                                    of the Master Servicer

                  (b)   See subparagraph (a)(3) above.

                  (c)   Not applicable.


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<PAGE>


                            ADDITIONAL INFORMATION


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

                  Not Applicable.


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

                  Not Applicable.


Item 1115(b) of Regulation AB.      Financial Information of Certain Entities
                                    Providing Derivative Instruments.

                  Not Applicable.


Item 1117 of Regulation AB.         Legal Proceedings.

                  None.


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

                  The Sponsor, the Company, the Issuing Entity, the Sellers
                  and the Master Servicer are affiliated parties. There are no
                  other affiliated parties. There are currently no business
                  relationships, agreements, arrangements, transactions or
                  understandings between (a) the Sponsor, the Company or the
                  Issuing Entity and (b) the Trustee, or any of its
                  affiliates, that were entered into outside the ordinary
                  course of business or that contain terms other than would be
                  obtained in an arm's length transaction with an unrelated
                  third party and that are material to the investor's
                  understanding of the Certificates. No such business
                  relationship, agreement, arrangement, transaction or
                  understanding has existed during the past two years.

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

                  See Exhibits 33.1, 33.2, 34.1 and 34.2 to this Form 10-K.


Item 1123 of Regulation AB.         Servicer Compliance Statement.

                  See Exhibit 35 to this Form 10-K.


                                      8
<PAGE>


                                  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.

         CHL MORTGAGE PASS-THROUGH TRUST 2007-HY4

                  By:   Countrywide Home Loans Servicing LP,
                           as Master Servicer

                        By:    Countrywide GP, Inc.

                               By:  /s/ Steve Bailey
                                    ------------------------------------
                                    Name:  Steve Bailey
                                    Title: Senior Managing Director,
                                    Chief Executive Officer Loan Administration
                                    (Senior officer in charge of the servicing
                                    function of Countrywide Home Loans Servicing
                                    LP)

                                    Date:  March 25, 2008


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<PAGE>


         SUPPLEMENTAL INFORMATION TO BE FURNISHED WITH REPORTS FILED PURSUANT
TO SECTION 15(d) OF THE ACT BY REGISTRANTS WHICH HAVE NOT REGISTERED
SECURITIES PURSUANT TO SECTION 12 OF THE ACT.

         No annual report, proxy statement, form of proxy or other proxy
soliciting material with respect to the Issuing Entity or the Depositor has
been, or will be, sent to security holders.


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<PAGE>


                                 EXHIBIT INDEX


Exhibit           Document
-------           --------


3(i)              Company's Certificate of Incorporation (Filed as Exhibit 3.1
                  to Registration Statement on Form S-3 (File No. 33-63714))*

3(ii)             Company's By-laws (Filed as Exhibit 3.2 to Registration
                  Statement on Form S-3 (File No. 33-63714)*

4                 Pooling and Servicing Agreement (Filed as part of the
                  Current Report on Form 8-K filed on October 10, 2007 under
                  the Commission file number of the Issuing Entity)*

31(ii)            Rule 15d-14(d) Certification

33.1              Report on Assessment of Compliance With Servicing Criteria
                  for Asset-Backed Securities for Countrywide Financial
                  Corporation

33.2              Report on Assessment of Compliance With Servicing Criteria
                  for Asset-Backed Securities for the Trustee

34.1              Attestation Report on Assessment of Compliance With
                  Servicing Criteria for Asset-Backed Securities of KPMG LLP
                  on behalf of Countrywide Financial Corporation

34.2              Attestation Report on Assessment of Compliance With
                  Servicing Criteria for Asset-Backed Securities of KPMG LLP
                  on behalf of the Trustee

35                Servicer Compliance Statement of the Master Servicer


____________

*        Incorporated herein by reference.


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