As Of                Filer                Filing    For·On·As Docs:Size              Issuer               Agent

 1/04/08  WaMu Mtge Pass-Through … 2007-OA4 15-15D      1/04/08    1:13K                                    Kelly Cecelia Anne/FA

Document/Exhibit                   Description                      Pages   Size 

 1: 15-15D      Notice of Suspension of Duty to File Reports        HTML     14K 

United States
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Form 15

CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITES EXCHANGE ACT OF 1934.

Commission File Number:  333-141255-02

WAMU ASSET ACCPETANCE CORP.
(Exact name of registrant as specified in its charter)

1301 SECOND AVENUE, WMC 3501A
SEATTLE, WASHINGTON 98101
 (206) 500-4418
(Address, including zip code, and telephone number, including area code, of registrant's principal executive offices)

WaMu Mortgage Pass-Through Certificates, Series 2007-OA4
(Title of each class of securities covered by this Form)

________________________________________________________
(Titles of all other classes of securities for which a duty to file reports under section 13(a) or 15(d) remains). Please place an X in the box(es) to designate the appropriate rule provisions(s) relied upon to terminate or suspend the duty to file reports:

Approximate number of holders of record as of the certification or notice date: NOT APPLICABLE.

Pursuant to the requirements of the Securities Exchange Act of 1934 has caused this certification/notice to be signed on its behalf by the undersigned duly authorized person.

Dated:   January 5, 2008

	WAMU ASSET ACCEPTANCE CORP. By:  /s/ Richard Careaga Richard Careaga First Vice President