The bulk polymerization of methyl methacrylate (MMA) initiated with diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS) was studied. This polymerization showed some "living" characteristics; that is, bath the yield and the molecular weight of the resulting polymers increased with reaction time, and the resultant polymer can be extended by adding MMA. The molecular weight distribution of PMMA obtained at high conversion is fairly narrow (M-w/M-n = 1.24 approximate to 1.34). It was confirmed that DCDPS can serve as a thermal iniferter for MMA polymerization by a "living" radical mechanism. Furthermore, the PMMA obtained can act as a macroinitiator for radical polymerization of styrene (St) to give a block copolymer.