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

  J.P. Morgan Chase Commercial Mortgage Securities Trust 2007-CIBC20
  Commercial Mortgage Pass-Through Certificates
  Series 2007-CIBC20 (the "Trust")

  I, Brian Baker, the President and Chief Executive Officer of J.P. Morgan
  Chase Commercial Mortgage Securities Corp., the depositor into the
  above-referenced Trust, certify that:

  1.I have reviewed this annual report on Form 10-K, and all reports on
    Form 10-D required to be filed in respect of period covered by this
    annual report on Form 10-K, of the Trust (the "Exchange Act Periodic
    Reports");

  2.Based on my knowledge, the Exchange Act Periodic Reports, taken as a
    whole, do not contain any untrue statement of a material fact or omit
    to state a material fact necessary to make the statements made, in
    light of the circumstances under which such statements
    were made, not misleading with respect to the period covered by this
    report;

  3.Based on my knowledge, all of the distribution, servicing and other
    information required to be provided under Form 10-D for the period
    covered by this report is included in the Exchange Act Periodic Reports;

  4.Based on my knowledge and the servicer compliance statements required
    in this report under Item 1123 of Regulation AB, and except as
    disclosed in the Exchange Act Periodic Reports, the master servicer and
    the special servicer have fulfilled their obligations under the pooling
    and servicing agreement in all material respects; and

  5.All of the reports on assessment of compliance with servicing criteria
    and their related attestation reports on assessment of compliance with
    servicing criteria required to be included in this report in accordance
    with Item 1122 of Regulation AB and Exchange Act Rules 13a-18 and
    15d-18 have been included as an exhibit to this report, except as
    otherwise disclosed in this report. Any material instances of
    noncompliance described in such reports have been disclosed in this
    report on Form 10-K.

    In giving the certifications above, I have reasonably relied on
    information provided to me by the following unaffiliated parties:
    Centerline Servicing Inc. as Special Servicer, J.E. Robert Company, Inc.
     as Special Servicer for the Sawgrass Mills loan, KeyCorp Real Estate
    Capital Markets, Inc. as Master Servicer for The USFS Industrial
    Distribution Portfolio loan, LaSalle Bank, National Association as
    Trustee for the Sawgrass Mills loan, LNR Partners, Inc. as Special
    Servicer for The USFS Industrial Distribution Portfolio loan, Midland
    Loan Services, Inc. as Master Servicer, Wells Fargo Bank, N.A. as
    Trustee, Wells Fargo Bank, N.A. as Paying Agent, Wells Fargo Bank, N.A.
    as Certificate Administrator and Trustee for The USFS Industrial
    Distribution Portfolio loan and Wells Fargo Bank, N.A. as Master
    Servicer for the Sawgrass Mills loan.

    Dated:   March 27, 2008


    /s/ Brian Baker
    Signature

    President and Chief Executive Officer
    J.P. Morgan Chase Commercial Mortgage Securities Corp.
    (senior officer in charge of securitization of the depositor)