Abstract: Objective:To investigate the osteoconduction of the rabbit's allograft bone surface-modified by polylysine.Methods:The surface of the micropores of the rabbit allograft bone was modified with polylysine using the lyophilization method(experimenal group),and the un-modified surface of the micropores of the rabbit allograft bone was set as control group.The rabbits' BMSCs were implanted into the surface of the micropores of the allograft bone in two groups,cultured and induced to osteoblasts.The attachment and proliferation of the cells on the surface of the micropores in the allograft bone in two groups were detected using SEM and MTT method,respectively.The activity of the alkaline phosphatase in two groups were evaluated.The allograft bone complicated with autologous cell was implanted into the bilateral radiuses defect of rabbits.The specimens were reconstructed by spiral CT after 1,2,3 and 4 months of treatment,and the regenerated bone was observed.Results:The attachment,proliferation and expression of ALP in experimental group were obviously better than those in control group(P<0.01).The recovery of defect lesion in experimental group was better than that in control group(P<0.01).Conclusions:The osteoconduction of the allograft bone surface-modified by polylysine can be significantly strengthened in vivo and in vitro.