Abstract： Objective To study the effect of the high molecular weight polyethylene on the periprosthetic tissue in diabetic model and investigate the effect of TNF-α in periprosthetic tissue.Methods Induction of experimental diabetes in rabbit with streptozotocin was performed successfully,every rabbit's lower limb was implanted a kirschner wire plug in femur by intereondylar notch.In experimental group,15 mg polyethylene particles,dispersed in 1.5 ml normal saline solution,were injected into one knee joint.The other knee joint was injected 1.5 ml normal saline solution ag control.This procedure was repeated for 2,4,6,8,10,and 12 weeks after the implantation.All animals were killed on the 2nd week after the last injection.Knee joint capsule tissues and periprosthetie tissues were examined by optical microscope.ELISA was used for determing the concentration of TNF-α.Results The results showed that kirschner wire were surrounded by multinueleated foreign-body giant cells and osteoclagt in the experimental group.Synovial membrane proliferation was obvious in the control group.There were no polyethylene particles and multinucleated foreign-body giant cells around plug in the marrpw.New bone wag found,kitschner wire was surrounded by suosteoblast,and normal synovial membrane was appeared.The concentration of TNF-α in experimental group was higher than that in control group.Conclusion Maximal ultra high molecular weight polyethylene and diabetic mellitus can restrain diabetic rabbit pefiprosthetic bone formation and increase the secretion of TNF-α.which may play an important role in the periprosthetic osteolysis.