3-Methoxy-4-(2-hydroxy-3-methacryloloxypropoxy)benzaldehyde (MHMPB) was prepared by reacting vanilline with glycidyl methacrylate in the presence of tetrabutylammonium bromide. Copolymers of MHMPB and methyl methacrylate (MMA) were prepared in dimethylformamide using azobisisobutyronitrile as the initiator. The compositions of the copolymers were determined by H-1 n.m.r. analysis and reactivity ratios were calculated using the Kelen-Tudos linear differential equation.