Statement of Changes of Beneficial Ownership

FORM 4
[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
                                                                                  
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public
Utility Holding Company Act of 1935 or Section 30(f) of the Investment Company Act of 1940
                      

1. Name and Address of Reporting Person *

ALCHIN JOHN R 		2. Issuer Name and Ticker or Trading Symbol

COMCAST CORP [ CMCSA ] 		5. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director                      _____ 10% Owner
__ X __ Officer (give title below)      _____ Other (specify below)
EVP, Treasurer & Co-CFO
(Last)          (First)          (Middle)

COMCAST CORPORATION, 1500 MARKET STREET 		3. Date of Earliest Transaction (MM/DD/YYYY)

12/2/2004
(Street)

PHILADELPHIA, PA 19102
(City)        (State)        (Zip)
4. If Amendment, Date Original Filed (MM/DD/YYYY)

 
6. Individual or Joint/Group Filing (Check Applicable Line)

_ X _ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3) 		2. Trans. Date 2A. Deemed Execution Date, if any 3. Trans. Code
(Instr. 8) 		4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5) 		5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4) 		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Class A Special Common Stock   (1) 12/2/2004     M    383863   A $7.5000   515835.9593   D  
 
Class A Special Common Stock   (1) 12/9/2004     M    13332   A $7.5000   529167.9593   D  
 
Class A Special Common Stock   (2) 12/9/2004     F    97671   D $30.5000   431496.9593   D  
 
Class A Special Common Stock   (3) 12/9/2004     F    120332   D $30.5000   311164.9593   D  
 
Class A Special Common Stock   12/10/2004     S    100000   D $30.5075   (4) 211164.9593   D  
 
Class A Special Common Stock                  29.2320   I   By 401(k)  

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 3) 		2. Conversion or Exercise Price of Derivative Security 3. Trans. Date 3A. Deemed Execution Date, if any 4. Trans. Code
(Instr. 8) 		5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5) 		6. Date Exercisable and Expiration Date 7. Title and Amount of Securities Underlying Derivative Security
(Instr. 3 and 4) 		8. Price of Derivative Security
(Instr. 5) 		9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Option to Purchase   (5) $7.5000   12/2/2004     M        383863      (6) 7/13/2005   Class A Special Common Stock   383863.0000   $0   63960.0000   D  
 
Option to Purchase   (5) $7.5000   12/9/2004     M        13332      (6) 1/13/2005   Class A Special Common Stock   13332.0000   $0   0.0000   D  
 

Explanation of Responses:
( 1)  Shares acquired upon exercise of options.
( 2)  Shares delivered for payment of option exercise price.
( 3)  Shares withheld for payment of tax liability.
( 4)  These shares were all sold on December 10, 2004, at prices ranging from $30.50 to $30.53 per share.
( 5)  This is an option to purchase Class A Special Common Stock.
( 6)  This option is immediately exercisable.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director 10% Owner Officer Other
ALCHIN JOHN R
COMCAST CORPORATION
1500 MARKET STREET
PHILADELPHIA, PA 19102

EVP, Treasurer & Co-CFO

Signatures
/s/ Alchin, John R. 12/13/2004
** Signature of Reporting Person Date


Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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