Reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) employing immobilized catalyst was approached at 50 and 60 degrees C in [C(8)mim]PF6, and compared with the polymerization of MMA DMF as solvent. Other ionic liquids, [C(6)mim]BF4, [C(8)mim]BF4, and [C(12)mim]BF4, were used as solvents to perform the RATRP of MMA. By comparison, we found that the [C(8)mim]PF6 was the best solvent in this immobilized catalyst system and the polymerization was best con-trolled. In addition, the immobilized catalyst spherules can easily separate from the reaction mixture, which avoids the prevalent problem of the catalyst residual in RATRP and also gives us a possibility to recycle the catalyst system. (c) 2006 Wiley Periodicals, Inc.