EXHIBIT 31.1

CERTIFICATION

I, Allen S. Greene, certify
that:

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|1. | I have reviewed this
 quarterly report on Form 10-Q of SmartPros Ltd.;                                                                                                                                                                                                                                                                     
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|2. | Based on my knowledge, this
 report does not contain any untrue statement of 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(s) 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 13a-15(f) and 15d-15(f)) 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) | Designed such internal
 control over financial reporting, or caused such internal control 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                                                                                                     
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|   |                                                                                                                                                                                                                                                                                                                                             | 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
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|5. | The registrants other
 certifying officer(s) 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):                                     
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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.                                                                                                                                                                                                                

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|----- | ----------------- | ----------------------------- | 
|Date: | November 10, 2009 |                              
|      |                   | /s/ ALLEN S. GREENE          
|      |                   |                               | 
|      |                   | Allen S. Greene              
|      |                   | Chief Executive Officer      
|      |                   | (Principal Executive Officer)

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