##### Table of Contents

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q

[X] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended June 30, 2010

OR

[ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR
15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from
 to

Commission File No. 333-113340-01

MEWBOURNE ENERGY PARTNERS 05-A, L.P.



|                                                         |  |  |  |                                        
|-------------------------------------------------------- |  |  |  | ---------------------------------------
|Delaware                                                 |  |  |  | 20-2306210                             
|(State or jurisdiction of incorporation or organization) |  |  |  | (I.R.S. Employer Identification Number)



|                                                                        
|------------------------------------------------------------------------
|3901 South Broadway, Tyler, Texas                      
     75701      
|(Address of principal executive offices)                    
 (Zip code)

Registrants Telephone Number, including area code:
(903) 561-2900





|                                                                                  
|----------------------------------------------------------------------------------
|Not Applicable                                                                    
|(Former name, former address and former fiscal year, if changed since last report)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 of 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Yes [X]    No [  ]

Indicate by check
mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the
preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes [  ]    No [  ]

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company in Rule
12b-2 of the Exchange Act. (Check one):

|                        |  |                                                     |  |                           |  |     
|----------------------- |  | --------------------------------------------------- |  | ------------------------- |  | ----
|Large accelerated filer |  | [  ]                                                |  | Accelerated filer         |  | [  ]
|Non-accelerated filer   |  | [  ]  (Do not check if a smaller reporting company) |  | Smaller reporting company |  | [X] 

Indicate by check mark if the registrant is a shell company (as defined in
Rule 12b-2 of the Exchange

Act).    Yes [  ]    No [X]



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##### Table of Contents

MEWBOURNE ENERGY PARTNERS 05-A, L.P.

INDEX



|                                                                                                                                                    |  |         
|--------------------------------------------------------------------------------------------------------------------------------------------------- |  | --------
|Part 1  -  Financial Information                                                                                                                    |  | Page No.
|                                                                                                                                                    | 
|Item 1. Financial Statements                                                                                                                        |  |         
|                                                                                                                                                    | 
|Condensed Balance Sheets - June 30, 2010 (Unaudited) and December 31, 2009                                                                          |  | 3       
|                                                                                                                                                    | 
|Condensed Statements of Operations (Unaudited) -For the three months ended June 
30, 2010 and 2009  and the six months ended June 30, 2010 and 2009 |  | 4       
|                                                                                                                                                    | 
|Condensed Statements of Cash Flows (Unaudited) - For the six months ended June 30, 2010 and
2009                                                    |  | 5       
|                                                                                                                                                    | 
|Condensed Statement of Changes In Partners Capital (Unaudited) -For the six months ended June 30,
2010                                             |  | 6       
|                                                                                                                                                    | 
|Notes to Condensed Financial Statements                                                                                                             |  | 7       
|                                                                                                                                                    | 
|Item 2. Managements Discussion and Analysis of Financial Condition and Results of Operations                                                       |  | 9       
|                                                                                                                                                    | 
|Item 3. Quantitative and Qualitative Disclosures about Market Risk                                                                                  |  | 12      
|                                                                                                                                                    | 
|Item 4. Disclosure Controls and Procedures                                                                                                          |  | 12      
|                                                                                                                                                    | 
|Part II  -  Other Information                                                                                                                       |  |         
|                                                                                                                                                    | 
|Item 1. Legal Proceedings                                                                                                                           |  | 13      
|                                                                                                                                                    | 
|Item 6. Exhibits and Reports on Form 8-K                                                                                                            |  | 13      



2



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MEWBOURNE ENERGY PARTNERS 05-A, L.P.

Part I - Financial Information

Item 1. Financial Statements

CONDENSED BALANCE SHEETS

June 30, 2010 and December 31, 2009



|                                                                      |             |               |              |                   |   |             
|--------------------------------------------------------------------- | ----------- | ------------- | ------------ | ----------------- | - | ------------
|                                                                      |             | June 30, 2010 |              | December 31, 2009
|                                                                      | (Unaudited) |               |             
|                                                                      |             |              
|ASSETS                                                                |             |               |              |                   |   |             
|                                                                      |             |              
|Cash                                                                  |             | $             | 83,863       |                   | $ | 15,159      
|Accounts receivable, affiliate                                        |             |               | 674,560      |                   |   | 708,677     
|Prepaid state taxes                                                   |             |               | 38,819       |                   |   | 27,333      
|                                                                      |             |               |              |                   |   |             
|Total current assets                                                  |             |               | 797,242      |                   |   | 751,169     
|                                                                      |             |               |              |                   |   |             
|                                                                      |             |              
|Oil and gas properties at cost, full-cost method                      |             |               | 30,119,052   |                   |   | 30,070,865  
|Less accumulated depreciation, depletion, amortization and impairment |             |               | (24,245,067) |                   |   | (23,869,828)
|                                                                      |             |               |              |                   |   |             
|                                                                      |             |               | 5,873,985    |                   |   | 6,201,037   
|                                                                      |             |               |              |                   |   |             
|                                                                      |             |              
|Total assets                                                          |             | $             | 6,671,227    |                   | $ | 6,952,206   
|                                                                      |             |               |              |                   |   |             
|                                                                      |             |              
|LIABILITIES AND PARTNERS CAPITAL                                     |             |               |              |                   |   |             
|                                                                      |             |              
|Accounts payable, affiliate                                           |             | $             | 106,642      |                   | $ | 103,622     
|                                                                      |             |               |              |                   |   |             
|Total current liabilities                                             |             |               | 106,642      |                   |   | 103,622     
|                                                                      |             |               |              |                   |   |             
|                                                                      |             |              
|Asset retirement obligation                                           |             |               | 181,126      |                   |   | 132,177     
|                                                                      |             |              
|Partners capital                                                     |             |               | 6,383,459    |                   |   | 6,716,407   
|                                                                      |             |               |              |                   |   |             
|                                                                      |             |              
|Total liabilities and partners capital                               |             | $             | 6,671,227    |                   | $ | 6,952,206   
|                                                                      |             |               |              |                   |   |             

The accompanying notes are an integral part of the financial
statements.



3



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MEWBOURNE ENERGY PARTNERS 05-A, L.P.

CONDENSED STATEMENTS OF OPERATIONS

For the three months ended June 30, 2010 and 2009 and

the six months ended June 30, 2010 and 2009

(Unaudited)



|                                                                                       |  |                              |           |                            |   |         |  |      |           |  |   |            
|-------------------------------------------------------------------------------------- |  | ---------------------------- | --------- | -------------------------- | - | ------- |  | ---- | --------- |  | - | -----------
|                                                                                       |  | Three Months Ended 
June 30, |           | Six Months Ended 
June 30,
|                                                                                       |  | 2010                         |           | 2009                       |   | 2010    |  | 2009
|Revenues and other income:                                                             |  |                              |           |                            |   |         |  |      |           |  |   |            
|Oil sales                                                                              |  | $                            | 238,291   |                            | $ | 91,688  |  | $    | 426,769   |  | $ | 180,489    
|Gas sales                                                                              |  |                              | 909,961   |                            |   | 354,826 |  |      | 2,017,883 |  |   | 1,200,798  
|Interest income                                                                        |  |                              | 52        |                            |   | 85      |  |      | 87        |  |   | 148        
|                                                                                       |  |                              |           |                            |   |         |  |      |           |  |   |            
|Total revenues and other income                                                        |  |                              | 1,148,304 |                            |   | 446,599 |  |      | 2,444,739 |  |   | 1,381,435  
|                                                                                       |  |                              |           |                            |   |         |  |      |           |  |   |            
|                                                                                       |  |                              |           |                           
|Expenses:                                                                              |  |                              |           |                            |   |         |  |      |           |  |   |            
|Lease operating expense                                                                |  |                              | 90,107    |                            |   | 81,152  |  |      | 217,376   |  |   | 185,532    
|Production taxes                                                                       |  |                              | 86,237    |                            |   | 27,083  |  |      | 186,032   |  |   | 96,071     
|Administrative and general expense                                                     |  |                              | 65,010    |                            |   | 64,024  |  |      | 106,408   |  |   | 121,809    
|Depreciation, depletion, and amortization                                              |  |                              | 188,910   |                            |   | 132,160 |  |      | 375,239   |  |   | 489,605    
|Cost ceiling write-down                                                                |  |                              | -         |                            |   | -       |  |      | -         |  |   | 4,960,963  
|Asset retirement obligation accretion                                                  |  |                              | 2,651     |                            |   | 2,280   |  |      | 4,940     |  |   | 4,501      
|                                                                                       |  |                              |           |                            |   |         |  |      |           |  |   |            
|Total expenses                                                                         |  |                              | 432,915   |                            |   | 306,699 |  |      | 889,995   |  |   | 5,858,481  
|                                                                                       |  |                              |           |                            |   |         |  |      |           |  |   |            
|                                                                                       |  |                              |           |                           
|Net income (loss)                                                                      |  | $                            | 715,389   |                            | $ | 139,900 |  | $    | 1,554,744 |  | $ | (4,477,046)
|                                                                                       |  |                              |           |                            |   |         |  |      |           |  |   |            
|                                                                                       |  |                              |           |                           
|Basic and diluted net income (loss) per partner interest(30,000 interests outstanding) |  | $                            | 23.85     |                            | $ | 4.66    |  | $    | 51.82     |  | $ | (149.23)   
|                                                                                       |  |                              |           |                            |   |         |  |      |           |  |   |            

The accompanying notes are an integral part of the financial
statements.



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MEWBOURNE ENERGY PARTNERS 05-A, L.P.

CONDENSED STATEMENTS OF CASH FLOWS

For the six months ended June 30, 2010 and 2009

(Unaudited)



|                                                                                            |  |                           |             |      |   |            
|------------------------------------------------------------------------------------------- |  | ------------------------- | ----------- | ---- | - | -----------
|                                                                                            |  | Six Months Ended
June 30,
|                                                                                            |  | 2010                      |             | 2009
|Cash flows from operating activities:                                                       |  |                           |             |      |   |            
|Net income (loss)                                                                           |  | $                         | 1,554,744   |      | $ | (4,477,046)
|Adjustments to reconcile net income (loss) to net cash provided by operating activities:    |  |                           |             |      |   |            
|Depreciation, depletion, and amortization                                                   |  |                           | 375,239     |      |   | 489,605    
|Cost ceiling write-down                                                                     |  |                           | -           |      |   | 4,960,963  
|Asset retirement obligation accretion                                                       |  |                           | 4,940       |      |   | 4,501      
|Changes in operating assets and liabilities:                                                |  |                           |             |      |   |            
|Accounts receivable, affiliate                                                              |  |                           | 34,117      |      |   | 643,674    
|Prepaid state taxes                                                                         |  |                           | (11,486)    |      |   | 27,758     
|Accounts payable, affiliate                                                                 |  |                           | 3,020       |      |   | (72,912)   
|                                                                                            |  |                           |             |      |   |            
|Net cash provided by operating activities                                                   |  |                           | 1,960,574   |      |   | 1,576,543  
|                                                                                            |  |                           |             |      |   |            
|                                                                                            |  |                          
|Cash flows from investing activities:                                                       |  |                           |             |      |   |            
|Purchase and development of oil and gas properties                                          |  |                           | (4,178)     |      |   | (50,331)   
|                                                                                            |  |                           |             |      |   |            
|Net cash used in investing activities                                                       |  |                           | (4,178)     |      |   | (50,331)   
|                                                                                            |  |                           |             |      |   |            
|                                                                                            |  |                          
|Cash flows from financing activities:                                                       |  |                           |             |      |   |            
|Cash distributions to partners                                                              |  |                           | (1,887,692) |      |   | (1,544,241)
|                                                                                            |  |                           |             |      |   |            
|Net cash used in financing activities                                                       |  |                           | (1,887,692) |      |   | (1,544,241)
|                                                                                            |  |                           |             |      |   |            
|                                                                                            |  |                          
|Net increase (decrease) in cash                                                             |  |                           | 68,704      |      |   | (18,029)   
|                                                                                            |  |                          
|Cash, beginning of period                                                                   |  |                           | 15,159      |      |   | 21,686     
|                                                                                            |  |                           |             |      |   |            
|                                                                                            |  |                          
|Cash, end of period                                                                         |  | $                         | 83,863      |      | $ | 3,657      
|                                                                                            |  |                           |             |      |   |            
|                                                                                            |  |                          
|Supplemental Cash Flow Information:                                                         |  |                           |             |      |   |            
|Non-cash changes to oil & gas properties related to asset retirement obligation liabilities |  | $                         | 44,009      |      | $ | 2,478      
|                                                                                            |  |                           |             |      |   |            

The accompanying notes are an integral part of the financial
statements.



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MEWBOURNE ENERGY PARTNERS 05-A, L.P.

CONDENSED STATEMENT OF CHANGES IN PARTNERS CAPITAL

For the six months ended June 30, 2010

(Unaudited)



|                             |  |                   |            
|---------------------------- |  | ----------------- | -----------
|                             |  | Partners Capital
|                             | 
|Balance at December 31, 2009 |  | $                 | 6,716,407  
|                             | 
|Cash distributions           |  |                   | (1,887,692)
|                             | 
|Net income                   |  |                   | 1,554,744  
|                             |  |                   |            
|                             | 
|Balance at June 30, 2010     |  | $                 | 6,383,459  
|                             |  |                   |            

The accompanying notes are an integral part of the financial
statements.



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##### Table of Contents

MEWBOURNE ENERGY PARTNERS 05-A, L.P.

NOTES TO CONDENSED FINANCIAL STATEMENTS

(Unaudited)



|1. | Description of Business
|-- | -----------------------

Mewbourne Energy Partners 05-A, L.P. (the Registrant or the Partnership), a Delaware limited partnership, is engaged
primarily in oil and gas development and production in Texas, Oklahoma, and New Mexico, and was organized on February 14, 2005. The offering of limited and general partnership interests began June 1, 2005 as a part of an offering
registered under the name Mewbourne Energy Partners 04-05 Drilling Program, (the Program), and concluded July 29, 2005, with total investor contributions of $30,000,000 originally being sold to 1,128 subscribers of which $26,844,000
were sold to 998 subscribers as general partner interests and $3,156,000 were sold to 130 subscribers as limited partner interests. During 2007, all general partner equity interests were converted to limited partner equity interests. In accordance
with the laws of the State of Delaware, Mewbourne Development Corporation (MD), a Delaware Corporation, has been appointed as the Partnerships managing general partner. MD has no significant equity interest in the Partnership.



|2. | Summary of Significant Accounting Policies
|-- | ------------------------------------------

Reference is hereby made to the Registrants Annual Report on Form 10-K for 2009, which contains a summary of significant accounting policies
followed by the Partnership in the preparation of its financial statements. These policies are also followed in preparing the quarterly report included herein.

In the opinion of management, the accompanying unaudited financial statements contain all adjustments of a normal recurring nature necessary to
present fairly our financial position, results of operations, cash flows and partners capital for the periods presented. The results of operations for the interim periods are not necessarily indicative of the final results expected for the
full year.

New Accounting Pronouncements

On April 20, 2010, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2010-14, Accounting for
Extractive Activities - Oil and Gas: Amendments to Paragraph 932-10-S99-1 to make the definitions in Accounting Standards Codification (ASC) 932-10-S99-1 consistent with those in the SEC Final Rule, Modernization of Oil and Gas
Accounting. The Partnership adopted the new standards effective December 31, 2009. This update had no effect on the Partnerships financial position, results of operations or cash flows.



|3. | Accounting for Oil and Gas Producing Activities
|-- | -----------------------------------------------

The Partnership follows the full-cost method of accounting for its oil and gas activities. Under the full-cost method, all productive and
non-productive costs incurred in the acquisition, exploration and development of oil and gas properties are capitalized. Depreciation, depletion and amortization of oil and gas properties subject to amortization is computed on the
units-of-production method based on the proved reserves underlying the oil and gas properties. At June 30, 2010 and 2009, all capitalized costs were subject to amortization. Proceeds from the sale or other disposition of properties are credited
to the full cost pool. Gains and losses on the sale or other disposition of properties are not recognized unless such adjustments would significantly alter the relationship between capitalized costs and the proved oil and gas reserves. Capitalized
costs are subject to a quarterly ceiling test that limits such costs to the aggregate of the present value of future net cash flows of proved reserves and the lower of cost or fair value of unproved properties. There were no cost ceiling write-downs
during the six months ended June 30, 2010. There was a cost ceiling write-down of $4,960,963 at March 31, 2009 but none at June 30, 2009.



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|4. | Asset Retirement Obligations
|-- | ----------------------------

The Partnership has recognized an estimated liability for future plugging and abandonment costs. The estimated liability is based on historical
experience and estimated well life. The liability is discounted using the credit-adjusted risk-free rate. Revisions to the liability could occur due to changes in well ownership interests, well plugging and abandonment costs or well useful lives, or
if federal or state regulators enact new well restoration requirements. The Partnership recognizes accretion expense in connection with the discounted liability over the remaining life of the well.

A reconciliation of the Partnerships liability for well plugging and abandonment costs for the six months ended June 30, 2010 and the
year ended December 31, 2009 is as follows:



|                             |  |               |         |                   |   |        
|---------------------------- |  | ------------- | ------- | ----------------- | - | -------
|                             |  | June 30, 2010 |         | December 31, 2009
|Balance, beginning of period |  | $             | 132,177 |                   | $ | 120,932
|Liabilities incurred         |  |               | 44,009  |                   |   | 2,487  
|Accretion expense            |  |               | 4,940   |                   |   | 8,758  
|                             |  |               |         |                   |   |        
|                             |  |              
|Balance, end of period       |  | $             | 181,126 |                   | $ | 132,177
|                             |  |               |         |                   |   |        



|4. | Related Party Transactions
|-- | --------------------------

In accordance with the laws of the State of Delaware, Mewbourne Development Corporation (MD), a Delaware Corporation, has been
appointed as the Partnerships managing general partner. MD has no significant equity interest in the Partnership. Mewbourne Oil Company (MOC) is operator of oil and gas properties owned by the Partnership. Mewbourne Holdings, Inc.
is the parent of both MD and MOC. Substantially all transactions are with MD and MOC.

In the ordinary course of business, MOC will
incur certain costs that will be passed on to owners of the well for which the costs were incurred. The Partnership will receive their portion of these costs based upon their ownership in each well incurring the costs. These costs are referred to as
operator charges and are standard and customary in the oil and gas industry. Operator charges include recovery of gas marketing costs, fixed rate overhead, supervision, pumping, and equipment furnished by the operator, some of which will be included
in the full cost pool pursuant to Rule 4-10(c)(2) of Regulation S-X. Services and operator charges are billed in accordance with the program and partnership agreements.

In consideration for services rendered by MD in managing the business of the Partnership, the Partnership during each of the initial six years of
the Partnership will pay to MD a management fee in the amount equal to .7% of the subscriptions by the investor partners to the Partnership. Effective January 1, 2006 the Partnership has elected to include the management fee as part of the full
cost pool pursuant to Rule 4-10(c)(2) of Regulation S-X.

In general, during any particular calendar year the total amount of
administrative expenses allocated to the Partnership by MOC shall not exceed the greater of (a) 3.5% of the Partnerships gross revenue from the sale of oil and natural gas production during each year (calculated without any deduction for
operating costs or other costs and expenses) or (b) the sum of $50,000 plus .25% of the capital contributions of limited and general partners.



8



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##### Table of Contents

The Partnership participates in oil and gas activities through a Drilling Program Agreement (the
Program). The Partnership and MD are parties to the Program. The costs and revenues of the Program are allocated to MD and the Partnership as follows:



|                                                                                                      |  |             |  |     
|----------------------------------------------------------------------------------------------------- |  | ----------- |  | ----
|                                                                                                      |  | Partnership |  | MD  
|Revenues:                                                                                             |  |             |  |     
|Proceeds from disposition of depreciable and depletable properties                                    |  | 70%         |  | 30% 
|All other revenues                                                                                    |  | 70%         |  | 30% 
|Costs and expenses:                                                                                   |  |             |  |     
|Organization and offering costs (1)                                                                   |  | 0%          |  | 100%
|Lease acquisition costs (1)                                                                           |  | 0%          |  | 100%
|Tangible and intangible drilling costs (1)                                                            |  | 100%        |  | 0%  
|Operating costs, reporting and legal expenses, general andadministrative expenses and all other costs |  | 70%         |  | 30% 



|(1) | Pursuant to the Program, MD must contribute 100% of organization and offering costs and lease acquisition costs which should approximate 20% of total capital
costs. To the extent that organization and offering costs and lease acquisition costs are less than 20% of total capital costs, MD is responsible for tangible drilling costs until its share of the Programs total capital costs reaches
approximately 20%. The Partnerships financial statements reflect its respective proportionate interest in the Program.
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Item 2.   Managements Discussion and Analysis of Financial Condition and Results of Operations

Liquidity and Capital
Resources

Mewbourne Energy Partners 05-A, L.P. was formed February 14, 2005. The offering of limited and general partnership
interests began June 1, 2005 and concluded July 29, 2005, with total investor contributions of $30,000,000. During 2007, all general partner equity interests were converted to limited partner equity interests.

Future capital requirements and operations will be conducted with available funds generated from oil and gas activities. No bank borrowing is
anticipated. The Partnership had net working capital of $690,600 at June 30, 2010.

During the six months ended June 30, 2010,
the Partnership made cash distributions to the investor partners in the amount of $1,887,692 as compared to $1,544,241 for the six months ended June 30, 2009. The Partnership expects that cash distributions will continue during 2010 as
additional oil and gas revenues are sufficient to produce cash flows from operations.

The sale of crude oil and natural gas produced by
the Partnership will be affected by a number of factors that are beyond the Partnerships control. These factors include the price of crude oil and natural gas, the fluctuating supply of and demand for these products, competitive fuels,
refining, transportation, extensive federal and state regulations governing the production and sale of crude oil and natural gas, and other competitive conditions. It is impossible to predict with any certainty the future effect of these factors on
the Partnership.



9



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##### Table of Contents

Results of Operations

For the three months ended June 30, 2010 as compared to the three months ended June 30, 2009:



|                  |  |                              |         |      |   |        
|----------------- |  | ---------------------------- | ------- | ---- | - | -------
|                  |  | Three Months Ended June 
30,
|                  |  | 2010                         |         | 2009
|Oil sales         |  | $                            | 238,291 |      | $ | 91,688 
|Barrels produced  |  |                              | 3,067   |      |   | 1,876  
|Average price/bbl |  | $                            | 77.70   |      | $ | 48.87  
|                  |  |                             
|Gas sales         |  | $                            | 909,961 |      | $ | 354,826
|Mcf produced      |  |                              | 190,026 |      |   | 113,053
|Average price/mcf |  | $                            | 4.79    |      | $ | 3.14   

Oil and gas revenues. As shown in
the above table, total oil and gas sales increased by $701,738, a 157.2% increase, for the three months ended June 30, 2010 as compared to the three months ended June 30, 2009.

Of this increase, $54,068 and $186,541 were due to increases in the average prices of oil and gas sold, respectively. Average prices rose to $77.70
from $48.87 per bbl and to $4.79 from $3.14 per mcf for the three months ended June 30, 2010 as compared to the three months ended June 30, 2009.

Also included in this increase were $92,535 and $368,594 due to increases in the volumes of oil and gas sold by 1,191 bbls and 76,973 mcf,
respectively. The lower volume for the three months ended June 30, 2009 was due to the curtailment of some of the Partnerships wells during April and May, 2009.

Lease operations. Lease operating expense during the three month period ended June 30, 2010 increased to $90,107 from $81,152 due to more well
repairs and workovers in the three month period ended June 30, 2010.

Production taxes. Production taxes during the three month
period ended June 30, 2010 increased to $86,237 from $27,083 for the three month period ended June 30, 2009 due to higher revenue.

Administrative and general expense. Administrative and general expense for the three month period ended June 30, 2010 was $65,010, which was
comparable to $64,024 for the three month period ended June 30, 2009.

Depreciation, depletion and amortization. Depreciation,
depletion and amortization for the three month period ended June 30, 2010 increased to $188,910 from $132,160 for the three month period ended June 30, 2009. This was due to an increase in production during the three month period ended
June 30, 2010.



10



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##### Table of Contents

Results of Operations

For the six months ended June 30, 2010 as compared to the six months ended June 30, 2009:



|                  |  |                     |           |      |   |          
|----------------- |  | ------------------- | --------- | ---- | - | ---------
|                  |  | Six Ended 
June 30,
|                  |  | 2010                |           | 2009
|Oil sales         |  | $                   | 426,769   |      | $ | 180,489  
|Barrels produced  |  |                     | 5,585     |      |   | 4,278    
|Average price/bbl |  | $                   | 76.41     |      | $ | 42.19    
|                  |  |                    
|Gas sales         |  | $                   | 2,017,883 |      | $ | 1,200,798
|Mcf produced      |  |                     | 377,025   |      |   | 288,623  
|Average price/mcf |  | $                   | 5.35      |      | $ | 4.16     

Oil and gas revenues. As shown in
the above table, total oil and gas sales increased by $1,063,365, a 77% increase, for the six months ended June 30, 2010 as compared to the six months ended June 30, 2009.

Of this increase, $146,408 and $343,947 were due to increases in the average prices of oil and gas sold, respectively. Average prices rose to
$76.41 from $42.19 per bbl and to $5.35 from $4.16 per mcf for the six months ended June 30, 2010 as compared to the six months ended June 30, 2009.

In addition, $99,872 and $473,138 were due to increases in the volumes of oil and gas sold by 1,307 bbls and 88,402 mcf. The lower volume for the
six months ended June 30, 2009 was due to the curtailment of some of the Partnerships wells during April and May, 2009.

Lease operations. Lease operating expense during the six month period ended June 30, 2010 increased to $217,376 from $185,532 due to more well
repairs and workovers in the six month period ended June 30, 2010.

Production taxes. Production taxes during the six month period
ended June 30, 2010 increased to $186,032 from $96,071 for the six month period ended June 30, 2009 due to higher revenue.

Administrative and general expense. Administrative and general expense for the six month period ended June 30, 2010 decreased to $106,408 from
$121,809 for the six month period ended June 30, 2009. The overall decrease was due to decreased administrative expenses allocable to the Partnership for the six month period ended June 30, 2010 and lower general expenses for reporting
costs.

Depreciation, depletion and amortization. Depreciation, depletion and amortization for the six month period ended June 30,
2010 decreased to $375,239 from $489,605 for the six month period ended June 30, 2009 due to a lower amortizable base at June 30, 2010. The reduced amortizable base was due to the March 31, 2009 cost ceiling write-down.

Cost ceiling write-down. There were no cost ceiling write-downs during the six months ended June 30, 2010. There was a cost ceiling write-down
of $4,960,963 at March 31, 2009 but none at June 30, 2009. The write-down was the result of lower oil and gas prices on that date.



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Item 3.   Quantitative and Qualitative Disclosures about Market Risk



|1. | Interest Rate Risk
|-- | ------------------

The Partnership Agreement
allows borrowings from banks or other financial sources of up to 20% of the total capital contributions to the Partnership without investor approval. Should the Partnership elect to borrow monies for additional development activity on Partnership
properties, it will be subject to the interest rate risk inherent in borrowing activities. Changes in interest rates could significantly affect the Partnerships results of operations and the amount of net cash flow available for partner
distributions. Also, to the extent that changes in interest rates affect general economic conditions, the Partnership will be affected by such changes.



|2. | Commodity Price Risk
|-- | --------------------

The
Partnership does not expect to engage in commodity futures trading or hedging activities or enter into derivative financial instrument transactions for trading or other speculative purposes. The Partnership currently expects to sell a
significant amount of its production from successful oil and gas wells on a month-to-month basis at market prices. Accordingly, the Partnership is at risk for the volatility in commodity prices inherent in the oil and gas industry, and the level of
commodity prices will have a significant impact on the Partnerships results of operations. For the six months ended June 30, 2010, a 10% change in the price received for natural gas production would have had an approximate $202,000 impact
on revenue.



|3. | Exchange Rate Risk
|-- | ------------------

The
Partnership currently has no income from foreign sources or operations in foreign countries that would subject it to currency exchange rate risk. The Partnership does not currently expect to purchase any prospects located outside of either the
United States or United States coastal waters in the Gulf of Mexico.

Item 4.   Disclosure
Controls and Procedures

MD maintains a system of controls and procedures designed to provide reasonable assurance as to the reliability
of the financial statements and other disclosures included in this report, as well as to safeguard assets from unauthorized use or disposition. MDs Chief Executive Officer and Chief Financial Officer have evaluated the effectiveness of the
design and operation of its disclosure controls and procedures with the assistance and participation of other members of management. Based upon that evaluation, MDs Chief Executive Officer and Chief Financial Officer concluded that its
disclosure controls and procedures are effective for gathering, analyzing and disclosing the information the Partnership is required to disclose in the reports it files under the Securities Exchange Act of 1934 within the time periods specified in
the SECs rules and forms. Since MDs December 31, 2009 annual report on internal control over financial reporting, and for the quarter ended June 30, 2010, there have been no changes in MDs internal controls or in other
factors which have materially affected, or are reasonably likely to materially affect, the internal controls over financial reporting.



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##### Table of Contents

Part II  Other Information

Item 1.   Legal Proceedings

From time to time, the Registrant may be a party to certain legal actions and claims arising in the ordinary course of business. While the outcome
of these events cannot be predicted with certainty, the Partnership does not expect these matters to have a material effect on its financial position or results of operations.

Item 6.   Exhibits and Reports on Form 8-K



| | (a) | Exhibits filed herewith.
| | --- | ------------------------



| | 31.1 | Certification of CEO Pursuant to Section 302 of Sarbanes-Oxley Act of 2002.
| | ---- | ---------------------------------------------------------------------------



| | 31.2 | Certification of CFO Pursuant to Section 302 of Sarbanes-Oxley Act of 2002.
| | ---- | ---------------------------------------------------------------------------



| | 32.1 | Certification of CEO Pursuant to Section 906 of Sarbanes-Oxley Act of 2002.
| | ---- | ---------------------------------------------------------------------------



| | 32.2 | Certification of CFO Pursuant to Section 906 of Sarbanes-Oxley Act of 2002.
| | ---- | ---------------------------------------------------------------------------



| | (b) | Reports on Form 8-K
| | --- | -------------------

None.



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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Partnership has duly caused this report to be signed on its behalf by the undersigned
thereto duly authorized.



|                                      |  |                                      |  |                                     
|------------------------------------- |  | ------------------------------------ |  | ------------------------------------
|                                      |  | Mewbourne Energy Partners 05-A, L.P.
|                                      |  |                                     
|                                      |  | By:                                  |  | Mewbourne Development Corporation   
|                                      |  |                                      |  | Managing General Partner            
|                                      |  |                                     
|Date:                 August 16, 2010 |  |                                      |  |                                     
|                                      |  |                                     
|                                      |  | By:                                  |  | /s/ Alan Clark                      
|                                      |  |                                      |  | Alan Clark, Treasurer and Controller



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INDEX TO EXHIBITS



|              |  |                                                                            
|------------- |  | ---------------------------------------------------------------------------
|EXHIBITNUMBER |  | DESCRIPTION                                                                
|              | 
|31.1          |  | Certification of CEO Pursuant to Section 302 of Sarbanes-Oxley Act of 2002.
|              | 
|31.2          |  | Certification of CFO Pursuant to Section 302 of Sarbanes-Oxley Act of 2002.
|              | 
|32.1          |  | Certification of CEO Pursuant to Section 906 of Sarbanes-Oxley Act of 2002.
|              | 
|32.2          |  | Certification of CFO Pursuant to Section 906 of Sarbanes-Oxley Act of 2002.



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