Diabetic vascular complications such as atherosclerosis have been reported as one of significant obstructions in treatment of diabetes. There has been a significant increase in recognition of the importance of antioxidative nutrients such as vitamin E, for the prevention of diabetic vascular complication by oxidative stress. This study focused on the effect of dietary $eta$-carotene on the levels of lipid peroxide and antioxidative vitamins of diabetic rats. The plasma glucose level, hepatic level of lipid peroxide and contents of antioxidants such as vitamins A and E were determined in STZ-induced diabetic rats. Dietary supplementation of B-carotene did not reduce the blood glucose in diabetic rats. Hepatic level of lipid peroxide tended to increase in diabetic rats, but $eta$-carotene intake reduced the value. Plasma levels of retinol and retinol/lipid were not changed by dietary supplementation of $eta$-carotene. There was no significant difference among experimental groups in plasma level of $alpha$-tocopherol. Hepatic levels of retionl and retinyl palmitate were increased by dietary supplementation of $eta$-carotene in diabetic rats. These results suggest that the supplementation of $eta$-carotene to the normal diet of diabetics may reduce the incidence of the diabetic vascular complications through the improvement of antioxidants depletion.