In order to improve the higher brittlement of wood resulted from in situ polymerization of glycidyl methacrylate(GMA), ethylene glycol dimethacrylate(EGDMA) with flexible chain was explored as toughness modifier to treat the wood GMA composite for higher impact toughness. GMA and EGDMA were mixed and impregnated into wood followed by in situ polymerization through heat treatment for the preparation of wood GMA EGDMA composite.The microscopic morphology, component characteristic and polymer aggregation state of wood GMA EGDMA composite were characterized by SEM, FTIR and XRD; and its impact toughness was also analyzed by impact toughness tester.The results indicate that the GMA and EGDMA mixed monomers polymerize into polymer in situ and evenly fill up wood cell lumen pores with amorphous form.The polymer interacts more strongly with wood.And impact fracture of polymer within the wood shows typical ductile fracture characteristic.The impact toughness of wood GMA EGDMA composite is improved by 98% and 220% over wood and wood GMA composite respectively.