**EXHIBIT
      31.1**





**ESSEX
      PORTFOLIO, L.P.**


**Certification
      of Principal Executive Officer**


**Pursuant
      to Section 302 of the Sarbanes-Oxley Act of 2002**








I,
      Keith
      R. Guericke, Principal Executive Officer of Essex Portfolio, L.P., certify
      that:





|1. | I
              have reviewed this quarterly report on Form 10-Q of Essex Portfolio,
              L.P.;
|-- | --------------------------------------------------------------------------------------------------------



|2. | Based
              on my knowledge, this report does 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, the financial statements, and other financial information
              included in this report, fairly present in all material respects the
              financial condition, results of operations and cash flows of the
              registrant as of, and for, the periods presented in this
              report;
|-- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|4. | The
              registrant’s other certifying officer and I are responsible for
              establishing and maintaining disclosure controls and procedures (as
              defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal
              control over financial reporting (as defined in Exchange Act Rules
              13(a) -
              15(f) and 15(d) - 15(f)) for the registrant and
              have:
|-- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|a) | Designed
              such disclosure controls and procedures, or caused such disclosure
              controls and procedures to be designed under our supervision, to ensure
              that material information relating to the registrant, including its
              consolidated subsidiaries, is made known to us by others within those
              entities, particularly during the period in which this report is being
              prepared;
|-- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|b) | Designed
              such internal controls over financial reporting, or caused such internal
              controls over financial reporting to be designed under our supervision,
              to
              provide reasonable assurance regarding the reliability of financial
              reporting and the preparation of financial statements for external
              purposes in accordance with generally accepted accounting
              principles;
|-- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|c) | Evaluated
              the effectiveness of the registrant’s disclosure controls and procedures
              and presented in this report our conclusions about the effectiveness
              of
              the disclosure controls and procedures, as of the end of the period
              covered by this report based on such evaluation;
              and
|-- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|d) | Disclosed
              in this report any change in the registrant’s internal control over
              financial reporting that occurred during the registrant’s most recent
              fiscal quarter (the registrant’s fourth fiscal quarter in the case of an
              annual report) that has materially affected, or is reasonably likely
              to
              materially affect, the registrant’s internal control over financial
              reporting; and
|-- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|5. | The
              registrant’s other certifying officer and I have disclosed, based on our
              most recent evaluation of internal control over financial reporting,
              to
              the registrant’s auditors and the audit committee of the registrant’s
              board of directors (or persons performing the equivalent
              functions):
|-- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------




a)
      All
      significant deficiencies and material weaknesses in the design or operation
      of
      internal control over financial reporting which are reasonably likely to
      adversely affect the registrant’s ability to record, process, summarize and
      report financial data; and




|b) | Any
              fraud, whether or not material, that involves management or other
              employees who have a significant role in the registrant’s internal control
              over financial reporting.
|-- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



Date:  August
      7,
      2006




/s/
      Keith R. Guericke


Keith
      R.
      Guericke


Chief
      Executive Officer and President,


Director
      and Vice Chairman of the Board,


Essex
      Property Trust, Inc., general partner of


Essex
      Portfolio, L.P.