This study was aimed to investigate the effects of resveratrol on plasma glucose and the oxidative stress ability in gestational diabetic rats. A total of 100 SD rats with gestation for 5 days were intraperitoneally injected with streptozotocin (STZ, 35 mg?kg-1) to prepare gestational diabetic rat model. Rats were randomly divided into 6 groups, which were the normal gestation group, gestational diabetic model group, resveratrol (30, 60, 120 and 240 mg?kg-1) treatment groups, with 20 rats in each group. A total of 20 rats with gestation for 5 days were selected as the normal gestation control group and another 20 rats with no gestation were selected as the normal control group. The levels of plasma glucose and insulin were determined on 0, 7, 14 days after experiment. Two weeks later, the contents of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in serum were determined. The results showed that compared with the normal control group, there were no significant difference on the levels of plasma glucose and insulin, the content of MDA, and the activities of SOD, GSH-Px and CAT of the normal gestation control group (P > 0.05). Compared with the gestational diabetic model group, the content of MDA in serum of the resveratrol (30, 60, 120 and 240 mg?kg-1) treatment groups were significantly decreased (P < 0.05,P < 0.01); the level of plasma glucose were significantly decreased and the level of insulin was significantly increased of the resveratrol (120 and 240 mg?kg-1) treatment groups (P < 0.05,P < 0.01); the activities of SOD, GSH-Px and CAT were also significantly increased (P < 0.05, P < 0.01). It was concluded that resveratrol had dose-dependent effect on reducing plasma glucose and improving antioxidant ability in gestational diabetic rats, which perhaps related to its effects on raising the level of insulin and improving the activity of antioxidant enzymes.