Exhibit 31.1

Certification of Chief Executive Officer pursuant to

Section 302 of the Sarbanes-Oxley Act of
2002

I, Charles J. Schreiber Jr., certify that:



|1. | I have reviewed this quarterly report on Form 10-Q of KBS Real Estate Investment Trust, Inc.;
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|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;
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|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;
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|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)) [Language omitted in accordance with SEC Release Nos. 34-47986 and 34-54942] for the registrant and have:
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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) [Paragraph
omitted in accordance with SEC transition instructions contained in SEC Release Nos. 34-47986 and 34-54942];

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 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:
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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 information; 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 14, 2007



/s/ Charles J. Schreiber, Jr.Charles J. Schreiber, Jr.Chairman of the Board, Chief Executive Officer and Director