Abstract: Ginseng polypeptide (GPP)isolated from the root of Panax ginseng C. A. Meyer was demonstrated to decrease the levels of blood sugar and livar glycogen when injected intravenously to rats at doses of 50～200 mg/kg without affecting total blood lipid. when mice were injected subcutaneously daily at doses of 50 and 100 mg/kg for 7 successive days, GPP was also found to decrease blood glucose and liver glycogen. In addition, GPP was found to decrease various experemental hyperglycemias induced by injection of adrenaline, glucose and alloxan However, GPP exhibited inhibiting effect on the glycogen enhancement induced by glucose, but strengthening effect on the glycogen decrease induced by adrenaline. When the levels of blood total lipid and liver glycogen were increased by alloxan, GPP was shown to inhibit these changes except its lowering of blood subar. The toxicity of GPP is very low, its iv LD₅₀ for mice was found to be 1.62±0.130 g/kg.