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                       State Street Research Capital Trust
                                  Certification
            Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
             (Subsections (a) and (b) of Section 1350, Chapter 63 of
                          Title 18, United States Code)

Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, the undersigned
officer of the State Street Research Capital Trust, a Massachusetts business
trust, (the "Trust"), does hereby certify that the Trust's report on Form
N-CSR for the period ended September 30, 2003 (the "N-CSR") fully complies
with the requirements of Section 13 (a) or 15 (d), as applicable, of the
Securities Exchange Act of 1934, as amended, and information contained in the
N-CSR fairly presents, in all material respects, the financial condition and
the results of operations of the Trust. This certification is provided solely
pursuant to 18 U.S.C. 1350 and shall not be deemed a part of the N-CSR, the
financial statements filed with the N-CSR or otherwise "filed" for any
purpose.

Date: December 3, 2003


                                          /s/ Douglas A. Romich
                                          Douglas A. Romich
                                          Treasurer

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                       State Street Research Capital Trust
                                  Certification
           Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
            (Subsections (a) and (b) of Section 1350, Chapter 63 of
                         Title 18, United States Code)

Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, the undersigned
officer of the State Street Research Capital Trust, a Massachusetts business
trust, (the "Trust"), does hereby certify that the Trust's report on Form
N-CSR for the period ended September 30, 2003 (the "N-CSR") fully complies
with the requirements of Section 13 (a) or 15 (d), as applicable, of the
Securities Exchange Act of 1934, as amended, and information contained in the
N-CSR fairly presents, in all material respects, the financial condition and
the results of operations of the Trust. This certification is provided solely
pursuant to 18 U.S.C. 1350 and shall not be deemed a part of the N-CSR, the
financial statements filed with the N-CSR or otherwise "filed" for any
purpose.

Date: December 3, 2003


                                /s/ Richard S. Davis
                                Richard S. Davis
                                President, Chairman and Chief Executive Officer