Effects of Mucilage fraction from Yam (Dioscorea batatas DECENE), which has long been used as a wild vegetable and folk medicine, on blood glucose and lipid composition in alloxan-induced diabetic mice were investigated. Diabetes mellitus was induced in male ICR mice by the injection of alloxan into the tail vein at a dose of 75 mg/kgBW. Alloxan-induced diabetic mice were administered the yam mucilage fraction1 orally ; y500F1 group (500 mg/kgBW/day fraction1) and y750F1 group (750 mg/kgBW/day fraction1); and the normal and alloxan-control group were orally administered with saline for 10 days. The body weight gain and food intake were monitored every day. The concentrations of glucose, triglyceride, total cholesterol, and LDL-cholesterol of serum and liver levels of glucose, triglyceride, and cholesterol were determined. Also weight of liver, heart, spleen and kidney were measured. The fraction 1 of yam mucilage lowered body weight gain significantly (p<0.05) and decreased serum glucose levels in alloxan-induced diatetic mice compared to that of alloxan-control group. In alloxan induced diabetic mice serum triglyceride level was lowered and liver HDL-cholesterol level increased significantly (p<0.05). In conclusion, it was assumed that yam mucilage fraction 1 has anti-hyperglycemic and anti-obesitic effects by reducing body weight gain and decreasing serum glucose and triglyceride level.