Exhibit (a)(1)

                            STATE STREET MASTER FUNDS
                   STATE STREET INSTITUTIONAL INVESTMENT TRUST

                   CODE OF ETHICS FOR PRINCIPAL EXECUTIVE AND
                            SENIOR FINANCIAL OFFICERS

I.    COVERED OFFICERS/PURPOSE OF THE CODE

      This Code of Ethics (the "Code") shall apply to the State Street Master
Funds' and State Street Institutional Investment Trust's (each a "Trust")
Principal Executive Officer, Principal Financial Officer, Controller, Principal
Accounting Officer and persons performing similar functions (the "Covered
Officers," each of whom is named in Exhibit A attached hereto) for the purpose
of promoting:

   -     honest and ethical conduct, including the ethical handling of actual or
         apparent conflicts of interest between personal and professional
         relationships;

   -     full, fair, accurate, timely and understandable disclosure in reports
         and documents that the Trust files with, or submits to, the Securities
         and Exchange Commission ("SEC") and in other public communications made
         by the Trust;

   -     compliance with applicable laws and governmental rules and regulations;

   -     the prompt internal reporting of violations of the Code to an
         appropriate person or persons identified in the Code; and

   -     accountability for adherence to the Code.

   Each Covered Officer should adhere to a high standard of business ethics and
   should be sensitive to situations that may give rise to actual as well as
   apparent conflicts of interest.

II. COVERED OFFICERS SHOULD HANDLE ETHICALLY ACTUAL AND APPARENT CONFLICTS OF
    INTEREST

OVERVIEW. A "conflict of interest" occurs when a Covered Officer's private
interest interferes with the interests of, or his service to, the Trust. For
example, a conflict of interest would arise if a Covered Officer, or a member of
his family, receives improper personal benefits as a result of his position with
the Trust. Covered Officers must avoid conduct that conflicts, or appears to
conflict, with their duties to the Trust. All Covered Officers should conduct
themselves such that a reasonable observer would have no grounds for belief that
a conflict of interest exists. Covered Officers are not permitted to self-deal
or otherwise to use their positions with the Trust to further their own or any
other related person's business opportunities.



      This Code does not, and is not intended to, repeat or replace the programs
and procedures or codes of ethics of the Trust's investment adviser or
distributor.

      Although typically not presenting an opportunity for improper personal
benefit, conflicts may arise from, or as a result of, the contractual
relationship between the Trust and its service providers, including investment
adviser, of which the Covered Officers may be officers or employees. As a
result, this Code recognizes that the Covered Officers will, in the normal
course of their duties (whether formally for the Trust, the investment adviser,
or other service providers), be involved in establishing policies and
implementing decisions that will have different effects on the service providers
and the Trust. The participation of the Covered Officers in such activities is
inherent in the contractual relationship between the Trust and its service
providers and is consistent with the performance by the Covered Officers of
their duties as officers of the Trust. Thus, if performed in conformity with the
provisions of the Investment Company Act of 1940, as amended ("Investment
Company Act") and the Investment Advisers Act of 1940, as amended ("Investment
Advisers Act"), such activities will be deemed to have been handled ethically.
In addition, it is recognized by the Trust's Boards of Trustees (the "Board")
that the Covered Officers may also be officers or employees of one or more other
investment companies covered by this or other codes.

      The following list provides examples of conflicts of interest under the
Code, but Covered Officers should keep in mind that these examples are not
exhaustive. The overarching principle is that the personal interest of a Covered
Officer should not be placed improperly before the interest of the Trust.

                    *          *            *          *

Each Covered Officer must not:

  -      use his or her personal influence or personal relationship improperly
         to influence investment decisions or financial reporting by the Trust
         whereby the Covered Officer would benefit personally to the detriment
         of the Trust;

  -      cause the Trust to take action, or fail to take action, for the
         individual personal benefit of the Covered Officer rather than the
         benefit of the Trust; or

  -      retaliate against any other Covered Officer or any employee of the
         Trust or their affiliated persons for reports of potential violations
         by the Trust of applicable rules and regulations that are made in good
         faith.

         Each Covered Officer must discuss certain material conflict of interest
  situations with the Trust's Audit Committee. Examples of such situations
  include:

  -      service as a director, trustee, general partner, or officer of any
         unaffiliated business organization. This rule does not apply to
         charitable, civic, religious, public, political, or social
         organizations, the activities of which do not conflict with the
         interests of the Trust;

  -      the receipt of any non-nominal gifts;



  -     the receipt of any entertainment from any company with which the Trust
        has current or prospective business dealings unless such entertainment
        is business-related, reasonable in cost, appropriate as to time and
        place, and not so frequent as raise any question of impropriety;

  -     any ownership interest in, or any consulting or employment relationship
        with, any of the Trust's service providers, other than its investment
        adviser, principal underwriter, administrator, transfer agent, custodian
        or any affiliated person thereof; and

  -     a direct or indirect financial interest in commissions, transaction
        charges or spreads paid by the Trust for effecting portfolio
        transactions or for selling or redeeming shares other than an interest
        arising from the Covered Officer's employment, such as compensation or
        equity ownership.

III. DISCLOSURE AND COMPLIANCE

  -     Each Covered Officer should familiarize himself or herself with the
        disclosure requirements generally applicable to the Trusts.

  -     Each Covered Officer should not knowingly misrepresent, or cause others
        to misrepresent, facts about the Trust to others, whether within or
        outside the Trust, including to the Trust's Board, Trust's Audit
        Committee and the Trust's independent auditors, and to governmental
        regulators and self-regulators and self-regulatory organizations.

  -     Each Covered Officer should, to the extent appropriate within his or her
        area of responsibility, consult with other officers and employees of the
        Trust and its service providers with the goal of promoting full, fair,
        accurate, timely and understandable disclosure in the reports and
        documents the Trust files with, or submits to, the SEC and in other
        public communications made by the Trust.

  -     It is the responsibility of each Covered Officer to promote and
        encourage professional integrity in all aspects of the Trusts'
        operations.

IV.   REPORTING AND ACCOUNTABILITY

        Each  Covered Officer must:

  -     upon adoption of this Code (or thereafter as applicable, upon becoming a
        Covered Officer), sign and return a report in the form of Exhibit B to
        the Trust's compliance officer affirming that he or she has received,
        read, and understands the Code;

  -     annually sign and return a report in the form of Exhibit C to the
        Trust's compliance officer as an affirmation that he or she has complied
        with the requirements of the Code; and



  -     notify the Trust's Audit Committee promptly if he or she knows of any
        violation of this Code. Failure to do so is itself a violation of this
        Code.

        The Trust's Audit Committee is responsible for applying this Code to
  specific situations in which questions are presented under it and has the
  authority to interpret this Code in any particular situation including any
  approvals or waivers sought by the Covered Persons.

        The Audit Committee will follow these procedures in investigating and
  enforcing this Code:

  -     The Audit Committee will take all appropriate actions to investigate any
        potential violations reported to the Committee.

  -     If, after such investigation, the Audit Committee believes that no
        violation has occurred, the Audit Committee is not required to take any
        further action.

  -     Any matter that the Audit Committee believes is a violation of this Code
        will be reported to the full Board.

  -     If the Board concurs that a violation has occurred, it will notify the
        appropriate personnel of the applicable service provider and may dismiss
        the Covered Officer as an officer of the Trust.

  -     The Audit Committee will be responsible for granting waivers of
        provisions of this Code, as appropriate.

  -     Any changes to or waivers of this Code will, to the extent required, be
        disclosed as provided by SEC rules.

V. OTHER POLICIES AND PROCEDURES

      This Code shall be the sole code of ethics adopted by the Trust for
  purposes of Section 406 of the Sarbanes-Oxley Act and the rules and forms
  applicable to registered investment companies thereunder. Insofar as other
  policies or procedures of the Trust, the Trust's investment adviser, principal
  underwriter, or other service providers govern or purport to govern the
  behavior or activities of the Covered Officers who are subject to this Code,
  they are superseded by this Code to the extend that they overlap or conflict
  with the provisions of this Code. The Trust's, investment adviser's and
  principal underwriter's codes of ethics under Rule 17j-1 under the Investment
  Company Act and the investment adviser's more detailed policies and procedures
  are separate requirements applying to the Covered Officers and others, and are
  not part of this Code.



VI. AMENDMENTS

      Any amendments to this Code, other than amendments to Exhibit A, must be
  approved or ratified by a majority vote of the Board, including a majority of
  independent Trustees.

VII. CONFIDENTIALITY

      All reports and records prepared or maintained pursuant to this Code will
  be considered confidential and shall be maintained and protected accordingly.
  Except as otherwise required by law or this Code, such matters shall not be
  disclosed to anyone other than the Trust's Board or Audit Committee.

VIII. INTERNAL USE

      The Code is intended solely for the internal use by the Trust and does not
  constitute an admission, by or on behalf of the Trust, as to any fact,
  circumstance, or legal conclusion.

  Date: September 18, 2003



EXHIBIT A

Persons Covered by this Code of Ethics:

Donald A. Gignac
President

Karen D. Gillogly
Treasurer



                                    EXHIBIT B

                           INITIAL CERTIFICATION FORM

      This is to certify that I have read and understand the Code of Ethics for
Principal Executive and Senior Financial Officers of State Street Master Funds
and State Street Institutional Investment Trust, dated September 18, 2003, and
that I recognize that I am subject to the provisions thereof and will comply
with the policy and procedures stated therein.

      Please sign your name here: __________________________________

      Please print your name here: _________________________________

      Please date here: ____________________________________________



                                    EXHIBIT C

                            ANNUAL CERTIFICATION FORM

      This is to certify that I have read and understand the Code of Ethics for
Principal Executive and Senior Financial Officers of State Street Master Funds
and State Street Institutional Investment Trust, dated September 18, 2003, (the
"Code") and that I recognize that I am subject to the provisions thereof and
will comply with the policy and procedures stated therein.

      This is to further certify that I have complied with the requirements of
the Code during the period of _____________ through ______________.

      Please sign your name here: ___________________________________

      Please print your name here: __________________________________

      Please date here: _____________________________________________