Abstract: The active fraction of Cyclocaryapaliurus(Batal.) Ijinskaja which inhibited α-glucosidase were screened,and studied its effects on hyperglycemiainmice with type Ⅱdiabetes mellitus. Column chromatography techniques were applied to isolate the total flavonoids and the total triterpenes. The preparation of total polysaccharides employed water extracting-alcohol precipitating and sevag method.The activity of inhibiting α-glucosidase was evaluated compared with acarbose in vitro. The oral glucose tolerance test(OGTT) in normal mice was applied to estimate the affection on postprandial blood sugar of total flavonoids from Cyclocaryapaliurus(CPF).The model of type Ⅱ diabetes mellitus was established by treating the mice with high-fat diet(HFD) and streptozotocin( STZ). CPF was administered orally at different doses to the diabetic mice. Fasting blood glucose(FBG),total glycerin(TG),total cholesterol(TC) were evaluated in normal and diabetic mice after four weeks. The concentration of total flavonoids from Cyclocaryapaliurus was 55.66%,it significantly inhibited glycosidic enzyme activityand its IC50 value of 60.477mg/L approached acarbose's IC50 value of 58.608mg/L.CPF markedly improved OGTT of normal mice and reduced FBG,TC and TG in mice with type Ⅱ diabetes mellitus. Hypoglycemic effect of Cyclocaryapaliurus associated with glycosidic enzyme inhibitory activity of flavonoids.