We investigated the effects of antioxidant vitamins supplementation on antioxidative status and plasma lipid profile in female Korean non-insulin diabetes mellitus(NIDDM) patients. Forty-five patients were groups by types of vitamin to take into three groups-Vitam in E group(400IU/day, n=15), Vitamin C group (1,000mg/day, n=15) and Vitamin E plus C group (400 IU plus 1,000mg/day). Supplementation period was 4 weeks. After vitamins supplementation, plasma vitamin E concentration significantly increased in vitamin E and vitamin E + C group, but plasma retinol concentration were not affected by vitamin E or vitamin C supplementation. And plasma levels of lipid peroxide measured as thiobarbituric acid reactive substances(TBARS), indicator of lipid peroxidation and increased susceptibility of LDL towards lipid peroxidation, were significantly decreased in all three groups after vitamins supplementation. Also catalase activities in erythrocytes were significantly decreased after antioxidant vitamin supplementation in all subjects. And after vitamins supplementation, post prandial 2 hour glucose and total cholesterol levels was decreased in all subjects. And after vitamins supplementation, post prandial 2 hour glucose and total cholesterol levels was decreased in all patients, especially there was a significant difference in vitamin C, Vitamin E + C group. In this study, antioxidant vitamins supplementation might have a protective function against the free radical-mediated lipid peroxidation and decrease the plasma total cholesterol levels in Korean female NIDDM patients.