Exhibit 12(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:

James E. Ross
President

Gary L. French
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: _________________________________________