Abstract: In order to prepare a polymer reinforced wood---based composite with excellent properties, a fast---growing wood, Populus ussuriensis Kom, and glycidyl methacrylate (GMA) as a difunctional monomer and methyl methacrylate (MMA) as an acrylate monomer were selected, and the monomers were impregnated into the porous structure of wood and further initiated by a catalyst---thermal treatment for their in situ polymerization. The composite’s structure was characterized by SEM, FTIR and XRD, and its corresponding properties were also tested. The results show that the contact between polymers and wood cell walls is tight, and the interfacial interaction is strengthened after adding GMA. GMA fully reacts with the hydroxyl group on wood cell walls by its epoxy group, and reacts with MMA in a free radical copolymerization form by its double bond. The copolymer, P(GMAcoMMA) is finally grafted onto wood cell walls in an amorphous form. The testing results of its properties show that the modulus of rupture (MOR), the dimensional stability, the decay resistance and the thermal stability of P(GMAcoMMA)/wood are increased by 90.53%, 54.05%, 92.85% and 31℃ compared with those of untreated wood, respectively.