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 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(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: January 31, 2005 Estimated average burden hours per response... 0.5

(Print or Type Responses)

1. Name and Address of Reporting Person * SMITH E FOLLIN   2. Issuer Name and Ticker or Trading Symbol CONSTELLATION ENERGY GROUP INC [CEG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CFO, CAO, Exec. VP - CEG (Last) (First) (Middle) 750 E. PRATT STREET 3. Date of Earliest Transaction (Month/Day/Year) 12/21/2005 (Street) BALTIMORE, MD 21202 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction 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 Common Stock 12/21/2005   M   71,363 (1) A $ 25.08 120,895 D   Common Stock 12/21/2005   M   206,000 (1) A $ 27.93 326,895 D   Common Stock 12/21/2005   M   50,000 (1) A $ 31.21 376,895 D   Common Stock 12/21/2005   M   42,227 (1) A $ 28.81 419,122 D   Common Stock 12/21/2005   M   23,097 (1) A $ 39.63 442,219 D   Common Stock 12/21/2005   F   271,684 (2) D $ 58.33 170,535 (3) D   Common Stock               131.3648 I By 401(k) Plan

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.		SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction 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 (Month/Day/Year)

7. Title and Amount of Underlying Securities (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

Stock Options (right to buy) (4)

$ 25.08

12/21/2005

M

71,363 (1)

(5)

11/12/2011

Common Stock

71,363

$ 0

0

D

Stock Options (right to buy) (4)

$ 58.33

12/21/2005

A

46,759 (6)

12/21/2005

11/12/2011

Common Stock

46,759

$ 0

46,759

D

Stock Options (right to buy) (4)

$ 27.93

12/21/2005

M

206,000 (1)

(7)

02/05/2012

Common Stock

206,000

$ 0

0

D

Stock Options (right to buy) (4)

$ 58.33

12/21/2005

A

141,067 (6)

12/21/2005

02/05/2012

Common Stock

141,067

$ 0

141,067

D

Stock Options (right to buy) (4)

$ 31.21

12/21/2005

M

50,000 (1)

(8)

05/24/2012

Common Stock

50,000

$ 0

0

D

Stock Options (right to buy) (4)

$ 58.33

12/21/2005

A

35,939 (6)

12/21/2005

05/24/2012

Common Stock

35,939

$ 0

35,939

D

Stock Options (right to buy) (4)

$ 28.81

12/21/2005

M

42,227 (1)

(9)

05/02/2013

Common Stock

42,227

$ 0

21,113

D

Stock Options (right to buy) (4)

$ 58.33

12/21/2005

A

29,301 (6)

12/21/2005

05/02/2013

Common Stock

29,301

$ 0

29,301

D

Stock Options (right to buy) (4)

$ 39.63

12/21/2005

M

23,097 (1)

(10)

02/26/2014

Common Stock

23,097

$ 0

46,193

D

Stock Options (right to buy) (4)

$ 58.33

12/21/2005

A

18,618 (6)

12/21/2005

02/26/2014

Common Stock

18,618

$ 0

18,618

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SMITH E FOLLIN 750 E. PRATT STREET BALTIMORE, MD 21202			CFO, CAO, Exec. VP - CEG

Signatures

Charles A. Berardesco, Attorney-in-Fact		12/22/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	At the request of the issuer, the officer has exercised all vested options held by such officer for purposes of minimizing the amount of excise taxes and tax gross-up payable by the issuer on behalf of the officer pursuant to Section 4999 of the Internal Revenue Code.
(2)	Shares were withheld to pay exercise prices and taxes due on the total of 392,687 stock options exercised on 12/21/05.
(3)	This amount includes shares obtained through reinvested dividends.
(4)	These are employee stock options.
(5)	Options vested in two installments on 7/1/02 and 7/1/03.
(6)	Represents replacement options granted to the officer following exercise of existing vested options on 12/21/05. The aggregate number of replacement options received is equal to the total number of options exercised less the actual shares received by the officer upon exercise of the options.
(7)	Options vested in three installments on 11/22/02, 11/23/03, and 11/24/04.
(8)	Options vested in three installments on 5/24/03, 5/24/04, and 5/24/05.
(9)	Options vest in three installments beginning on 5/2/04. The second installment vested on 5/2/05, and the third installment will vest on 5/2/06.
(10)	Options vest in three installments beginning on 2/26/05. The second and third installments will vest on 2/26/06 and 2/26/07, respectively.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.