In the present study, we intended to evaluate the hypoglycemic effect of Gi-In-Bu-Shen-Fang (abbrev. GIBSF) on streptozotocin (STZ)-induced diabetic rats. We also detected the levels of cholesterol, triglyceride in the serum and the levels of SOD GSH, GSH-Px, in the liver, kidney and brain. The results shown that GIBSF decreased the blood sugar levels of diabetic rats induced by streptozotocin. Concentration of serum cholesterol and triglyceride and activities of SOD, GSH and GSH-Px were increased and function of glucose tolerance was improved. These results suggested that GIBSF possessed hypoglycemic effect in STZ-treated rats. The hypoglycemic mechanisms were related to the increase in the activities of SOD, GSH and GSH-Px.