This study was designed to examine the influences of antioxidants on toxicity of paraquat in male rats. Paraquat and ascorbic acid were given orally ad libitum with tap water containing paraquat 30 ppm and 100 ppm and ascorbic acid 1000ppm for 10 days, respectively, alpha-tocopherol(60 mg/kg) was administered orally by sonde at 2 days intervals for 10 days. Paraquat at given doses produced markedly a dose-related reduction in water-intake, ratio of liver weight/body weight and glutathione along with the increased aspartate aminotransferase, alkaline phosphatase, serum lipid and ratio of lung weight/body weight. However the combined administration of ascorbic acid and paraquat did not affect the toxic effects of paraquat, whereas combined administration of paraquat and alpha-tocopherol showed relative reduction in the toxicities of paraquat. From these experimental results, it could be concluded that alpha-tocopherol has detoxifying effect on paraquat poisoning as the antioxidant, meanwhile ascorbic acid, one of the antioxidance, does not exert any detoxifying effects.