The effect of fullerene (C 60 ) on the radical polymerization of methyl methacrylate (MMA) in benzene was studied kinetically and by means of ESR, where dimethyl 2,2ะ-azobis(isobutyrate) (MAIB) was used as initiator. The polymerization rate (R p ) and the molecular weight of resulting poly(MMA) decreased with increasing C 60 concentration ((0 -2.11) ฯซ 10 ฯช4 mol/L). The molecular weight of polymer tended to increase with time at higher C 60 concentrations. R p at 50ยฐC in the presence of C 60 (7.0 ฯซ 10 ฯช5 mol/L) was expressed by R p ฯญ k[MAIB] 0.5 [MMA] 1.25 . The overall activation energy of polymerization at 7.0 ฯซ 10 ฯช5 mol/L of C 60 concentration was calculated to be 23.2 kcal/mol. Persistent fullerene radicals were observed by ESR in the polymerization system. The concentration of fullerene radicals was found to increase linearly with time and then be saturated. The rate of fullerene radical formation increased with MAIB concentration. Thermal polymerization of styrene (St) in the presence of resulting poly(MMA) seemed to yield a starlike copolymer carrying poly(MMA) and poly(St) arms. The results (r 1 ฯญ 0.53, r 2 ฯญ 0.56) of copolymerization of MMA and St with MAIB at 60ยฐC in the presence of C 60 (7.15 ฯซ 10 ฯช5 mol/L) were similar to those (r 1 ฯญ 0.46, r 2 ฯญ 0.52) in the absence of C 60 .