Effects on the feeds of streptozotocin-induced diabetic rats with a giant embryonic rice on lipid peroxides level and antioxidative enzyme activites in plasma and liver tissues were investigated. Along with the experimental periods, all animals in diabetic groups had a lower increase rate in body weight than the normal control group. A giant embryonic rice-fed group showed a inhibition in the decrease of body weight, and a increase in feed intake compared to the normal control group. The organ weights of the diabetic control group were heavier than those of the normal control while rice-fed groups including the giant embryonic rice-fed group were found to have lower organ weights, and its blood sugar level was found to be lower than those of the normal group. Lipid peroxides of the giant embryonic rice-fed animals showed a lower lipid peroxidation values compared to that of the diabetic control group. Plasma vitamin A and E concentrations of the diabetic control group were significantly decreased compared to the normal control while those of the giant embryonic rice-fed group were found to be significantly higher than those of the diabetic control. Of the hepatic antioxidative enzymes, SOD activity of the giant embryonic rice-fed group was higher than that of the diabetic control group. Taken these together, low lipid peroxidation values and, in contrast, high antioxidative enzyme activities were thought to be a cause for decreasing hepatic oxidative damages.