The dried powder of cultural mycelium of ordyceps sinensis was extractedwith 1.25 mol ? L-1sodium hydroxide and precipitated with ethanol to afford the CsOH, in 2.58% yield. CsOH was consisted of 5 monosaccharide measured by paper chromatogra-phy (PPC) and gas- liquid chromatography (GLC). CsOH given intragastrically at the dose of 500 mg?kg-1and 250 mg?kg-1,ip at a dose of 100 mg?kg-1and 50 mg?kg-1had significant hypoglycemic activities in normal mice, alloxan-induced diabetes mice and streptozotocin-induced diabetes mice, and showed a dose-effect relation.