The purpose of this study was to investigate the effects of vitamin E supplementation on the activities of antioxidative enzymes in liver of KK mice of various ages and various duration of diabetes. Diabetes was induced by feeding high fat diet containing 20% corn oil(wt/wt). Weaned KK mice were fed high fat diet containing 51 IU or 2080 IU vitamin E per kg diet. Animals were sacrificed at 4, 6, and 9 months of age. In nondiabetic group, we found the decrease of antionxidative enzyme activities with aging. In diabetic group, antioxidative enzyme activities were decreased, and the change of hepatic vitamin E was related to glutathione peroxidase activity (r=0.71, p<0.001). Treatment with vitamin E did not modify the level of fasting blood glucose. However, it was observered that glutathione reductase and glutathione peroxidase activities as well as hepatic glutathione levels were increased by vitamie E supplementation, whereas catalase activity did not changed. The present result suggest that high vitamin E supplementation protects against lipid peroxidative damage in diabetic KK mice.