A C-60 derivative, benzylaminofullerene (BZAF) with a stoichiometry of [C60H1.9(NHC6H5)(1.9)] was synthesized by nucleophilic addition of fullerene with benzylamine in DMSO/o-dichlorobenzene. Free radical copolymerization of BZAF with methyl methacrylate or ethyl methacrylate gave high yields of copolymers. The optical limiting threshold of BZAF is comparable with that of C-60 and stronger than those of the copolymers.