**Exhibit 31.1**

 

Certification of Principal Executive Officer

Pursuant to Rule 13a-14(a) of theSecurities Exchange Act of 1934

 

I,Michael J. Mauceli, certify that:

 

1.     I have reviewed this quarterly report on Form 10-Qfor the fiscal quarter ended September 30, 2007 of Reef Global Energy IX,L.P.;

 

2.     Based on my knowledge, this report does notcontain any untrue statement of a material fact or omit to state a materialfact necessary to make the statements made, in light of the circumstances underwhich such statements were made, not misleading with respect to the periodcovered by this report;

 

3.     Based on my knowledge, the financial statements,and other financial information included in this report, fairly present in allmaterial respects the financial condition, results of operations and cash flowsof the registrant as of, and for, the periods presented in this report;

 

4.     The registrant’s other certifying officer and Iare responsible for establishing and maintaining disclosure controls andprocedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e))for the registrant and have:

 

a)     Designedsuch disclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that material informationrelating to the registrant, including its consolidated subsidiaries, is madeknown to us by others within those entities, particularly during the period inwhich this report is being prepared;

 

b)    Evaluatedthe effectiveness of the registrant’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period covered by thisreport based on such evaluation; and

 

c)     Disclosed inthis report any change in the registrant’s internal control over financialreporting that occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that hasmaterially affected, or is reasonably likely to materially affect, theregistrant’s internal control over financial reporting; and

 

5.     The registrant’s other certifying officer and Ihave disclosed, based on our most recent evaluation of internal control overfinancial reporting, to the registrant’s auditors and the audit committee ofregistrant’s board of directors (or persons performing the equivalentfunctions):

 

a)     Allsignificant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely toadversely affect the registrant’s ability to record, process, summarize andreport financial information; and

 

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

 
| Date: November 14, 2007 | By: Reef Oil & Gas Partners, L.P.    |
|------------------------------|-----------------------------------------------|
|                         | Managing General Partner                      |
|                         |                                          |
|                         | By: Reef Oil & Gas Partners, GP, LLC |
|                         |                                          |
|                         | By:                                           |  /s/ Michael J. Mauceli |   |
|                         | Michael J. Mauceli                            |
|                         | Manager and Member                            |
|                         | (principal executive officer)                 |

 

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