UNITED STATES SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM 3
INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

    Filing 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

   CHEBEIR, CAMILLE A.
   Sedco Services, Inc.
   33 East 67th Street
   New York, New York  10021

2. Date of Event Requiring Statement (Month/Day/Year)

   03/23/99

3. IRS or Social Security Number of Reporting Person (Voluntary)
   
4. Issuer Name and Ticker or Trading Symbol

   HYBRIDON, INC.
   HYBN

5. Relationship of Reporting Person(s) to Issuer (Check all applicable)
   (X) Director  ( ) 10% Owner  ( ) Officer (give title below) ( ) Other
   (specify below)

6. If Amendment, Date of Original (Month/Day/Year)
   
7. 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 Beneficially Owned                                                                           |
___________________________________________________________________________________________________________________________________|
1. Title of Security                       |2. Amount of          |3. Ownership    |4. Nature of Indirect                          |
                                           |   Securities         |   Form:        |   Beneficial Ownership                        |
                                           |   Beneficially       |   Direct(D) or |                                               |
                                           |   Owned              |   Indirect(I)  |                                               |
___________________________________________________________________________________________________________________________________|
                                                                          
COMMON STOCK                               |25,000                |D               |                                               |
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                                           |                      |                |                                               |
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                                           |                      |                |                                               |
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                                           |                      |                |                                               |
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Reminder:  Report on a separate line for each class of securities beneficially owned directly or indirectly.                 (Over)

                                                (Print or Type Responses)                                              SEC1473(3/91)

 *If the Form is filed by more than one Reporting Person, see Instruction 5(b)(v).
**Effective October 1, 1997                                                                          Page 1 of 2




Form 3 (continued) Table II - Derivative Securitites Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities) ___________________________________________________________________________________________________________________________________ Table II -- Derivative Securitites Beneficially Owned | ___________________________________________________________________________________________________________________________________| 1.Title of Derivative |2.Date Exer- |3.Title and Amount | |4. Conver-|5. Owner- |6. Nature of Indirect | Security | cisable and | of Underlying | |sion or |ship | Beneficial Ownership | | Expiration | Securities | |exercise |Form of | | | Date(Month/ |-----------------------|---------|price of |Deriv- | | | Day/Year) | |Amount |deri- |ative | | | Date | Expira- | |or |vative |Security: | | | Exer- | tion | Title |Number of|Security |Direct(D) or | | | cisable | Date | |Shares | |Indirect(I) | | ___________________________________________________________________________________________________________________________________| ___________________________________________________________________________________________________________________________________| ___________________________________________________________________________________________________________________________________| ___________________________________________________________________________________________________________________________________| ___________________________________________________________________________________________________________________________________| ___________________________________________________________________________________________________________________________________| Explanation of Responses: ***Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S. C. 78ff(a). /s/ Camille A. Chebeir - --------------------------- By: Camille A. Chebeir 04/30/99 - -------- DATE Note: File three copies of this Form, one of which must be manually signed. If space provided 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. Page 2 of 2