We investigated the effects of vitamin E supplementation on the protein glycosylation in vivo. Weaned KK-mice were fed high fat diet containing 20% corn oil(wt/wt), and sacrificed at 4, 6, and 0 months of age. High vitamin E diet was the high fat diet supplemented with an excess amount of 이-$alpha$-tocopheryl acetate(2080IU/kg diet). We measured $HbA_{1C}$ as a glycosylation early product, and collagen-linked fluorescence (CLF) of skin as a glycosylation and product. We found that diabetic group had increased levels of $HbA_{1C}$ within 2 months after onset of diabetes and during the experiments. The skin CLF increased dramatically 5 months after onset of diabetics. Treatment with vitamin E did not modify the level of blood glucose. However, we observed a significant lowering in CLF and $HbA_{1C}$ in diabetic mice