Abstract: In order to investigate the role of ginsenoside Rb₃ in the therapy of diabetes and its mechanisms, the streptozocin-induced diabetic mice model was constructed and the effects of ginsenoside Rb₃ on serum glucose, serum lipid, insulin and antioxidative indices were systematically studied. The detection of fasting blood glucose levels indicated that 14 d treatment with ginsenoside Rb₃ via intragastric administration had a significant （P<0.01）hypoglycemic activity on diabetic mice and the concentration of 30 mg·kg^-1 had more effective therapy results, which was equivalent to that of diabetic medicine metformin hydrochloride. The effects of ginsenoside Rb₃ on serum total cholesterol (TC), glycerin trimyristate (TG) and insulin(INS) were analyzed and the results showed that the Rb₃ had a significant regulatory function to decrease the concentration of serum lipid, which increased that of insulin in diabetic mice. The dose of 30 mg·kg^-1 Rb₃ was more effective than that of metformin hydrochloride. The antioxdative effects of Rb₃ were evaluated and the results illustrated that the activity of superoxide dismutase(SOD) had greatly increased, while the content of malonaldehyde (MDA) had obviously decreased in diabetic mice after the treatment of Rb₃, which was significant in improving the antioxdative ability and relieving diabetic complication.