The purpose of this study was to investigate the effect of vitamin E supplementation on the lipid peroxidation and activities of antioxidative enzymes in the pancreas of diabetic KK mice. KK mice were fed high ft diet containing 20% corn oil(wt/wt), and sacrificed at 2 months of diabetes. A hish vitamin E diet consisted of the high fat diet supplemented with an excessive amount of 이-$alpha$-tocopheryl acetate (2080IU/kg diet). The incidence of diabetes mellitus was 61% when mice were fed the high fat diet, but was 44% when mice were fed the high vitamin E diet, Vitamin E supplementation fhus seems to have the effect of decreasing of decreasing the onset of diaetes. In the diabetic group, we found increases of MDA (malondialdehyde) and antioxidative enzyme activities. Treatment with vitamin E did not modify the level of fasting blood glucose. However, MDA and antiosicative enzyme activities in diabetic mice were decreased by the high vitamin E diet. Increased levels of lipid peroxidation products suggests the occurrence of oxidative damage in the pancreas of diabetic mice. The increased level of antiosicative enzyme activities could be due to an adaptive response to conditions of increased peroxidative stress. Significant normalization on catalase activity was noted in vitamin E supplemented animals.