The polar wood impregnated with monomer MMA at room temperature and atmospheric pressure was irradiated by 60Co γ-rays. The effects of impregnation time and absorbed dose on mechanical properties of polar wood were investigated, and the changes of wood section before and after irradiation were charactered by ESEM. The results showed that the compressive strength of arrange grain, MOR and MOE increased by 72.3%, 72%, and 42.5%, respectively, when the impregnation time was 48 h and the absorbed dose 20 kGy. The polar cell wall is full of polymer and forms obvious granular polymer after irradiation and the mechanical properties are improved greatly.Cited