1. Name and Address of Reporting Person Wobby, Daniel S. c/o Cabot Microelectronics Corporation 870 Commons Drive Aurora, IL 60504 USA 2. Issuer Name and Ticker or Trading Symbol Cabot Microelectronics Corporation (CCMP) 3. IRS or Social Security Number of Reporting Person (Voluntary) 4. Statement for Month/Day/Year 01/03/2003 R1 5. If Amendment, Date of Original (Month/Day/Year) 01/06/2003 6. Relationship of Reporting Person(s) to Issuer (Check all applicable) ( ) Director ( ) 10% Owner (X) Officer (give title below) ( ) Other (specify below) Principal Accounting Officer 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 Acquired, Disposed of, or Beneficially Owned +------------------------------+----------+----------+---------+--------------------------+--------------+-----------+------------+ |1. Title of Security |2. Trans- |2A.Execu- |3. Trans-|4. Securities Acquired (A)|5. Amount of |6. Owner- |7. Nature | | | action | action | action| or Disposed of (D) |Securities | ship | of In- | | | Date | Date | Code | |Beneficially | Form: | direct | | | | | | |Owned | Direct | Bene- | | | (Month/ | (Month/ | | |Following | (D) or | ficial | | | Day/ | Day/ +-----+---+-----------+---+----------+Reported | Indirect| Owner- | | | Year) | Year) |Code |V |Amount |A/D|Price |Transaction(s)| (I) | ship | +------------------------------+----------+----------+-----+---+-----------+---+----------+--------------+-----------+------------+ Common Stock 12/31/2002 A 259 A $34.9900 5082 D TABLE II -- Derivative Securities Acquired, Disposed of, or Beneficially Owned +----------+--------+-------+-------+---------+-----------+---------------------+----------------+----------+-------+-------+------+ |1. |2. |3. |3A. |4. |5. |6. |7. |8. |9. |10. |11. | | | | | | | | | | |Number |Owner- | | | | | | | | | | | |of |ship | | | | | | | | | | | |Deriv- |Form of| | | | | | | | | |Title and Amount| |ative |Deriv- | | | | | | | | | |of Underlying | |Secur- |ative |Nature| | |Conver- |Trans- |Execu- | |Number of | |Securities | |ities |Secur- |of | | |sion or |action |tion | |Derivative |Date Exercisable +-------+--------+ |Benefi-|ity: |In- | | |Exercise|Date |Date | |Securities |and Expiration Date | |Amount | |cially |Direct |direct| | |Price of| | |Transac- |Acquired(A)|(Month/Day/Year) | |or | |Owned |(D) or |Bene- | |Title of |Deriv- |(Month/|(Month/|tion Code|Disposed(D)+----------+----------+ |Number |Price of | |In- |ficial| |Derivative|ative | Day/ | Day/ +------+--+-----+-----+Date Exer-|Expira- | |of |Derivative| |direct |Owner-| |Security |Security|Year) |Year) |Code |V |(A) |(D) |cisable |tion Date |Title |Shares |Security | |(I) |ship | +----------+--------+-------+-------+------+--+-----+-----+----------+----------+-------+--------+----------+-------+-------+------+ Stock $20 04/03/2005 Common 10000 D Options Stock (Right to buy) Stock $49.8 05/01/2012 Common 4000 D Options Stock (Right to buy) Stock $51.37 12/11/2012 Common 6000 D Options Stock (Right to buy) Stock $67.07 05/01/2008 Common 11500 D Options Stock (Right to buy) Explanation of Responses: SIGNATURE OF REPORTING PERSON /s/ Daniel S. Wobby DATE 01/09/2003