As one of the ways to obtain high polymers which have chemical reactivity, copolymers of glycidyl methacrylate with each methyl methacrylate and methyl acrylate were prepared using benzoyl peroxide as free radical catalyst in bulk. Monomer reactivity ratios of glycidyl methacrylate-methyl methacrylate copolymerization, and for glycidyl methacrylate-methyl acrylate copolymerization were respectively determined. The Q-and e-values according to Alfrey-P_<RICF>, were obtained from their monomer reactivity ratios in the copolymerization with each methyl methacrylate and methyl acrylate.