Mulberry leaves(Mori folium) and silkworm(Bombyx mori) are potnet inhibiters of intestinal $alpha$-glycosidase, and inhibit the digestion of starch and sucrose in the small intestine. They are able to prevent postprandial hyperglycemia and decrease blood insulin levels. In this study , a high-carbohydrate diet(CHO ; 67.5%, protein ; 20.8%, fat : 11.7%) was received by the control group. In contrast, the experimental groups received a high-carbohydrate diet with extracts of mulberry leaves and silkwork(50mg.100g diet), and acarbose(6.7mg/100g diet). after a 10 week study period , the experimental groups had lower blood glucose and triglyceride levels. The experimental groups tended to have lwer Hb Alc levels. Also, blood insulin levels were lower than the control groups in accordance with blood glucose levels. The activities of intestinal $alpha$-glucosidase in the middle and distal parts of small intestine were induced by the extracts of mulberry leaves and silkworm in the experimental groups. However, the activities of liver lysosomal glucosidase and the contents of glycogen in the liver were not affected by the mulberry leave and silkworm extracts nor by acarbose. Mulberry leaves and silkworm were able to prevent sudden postprandial peaks in blood glucose as a result of $alpha$-glycosidase, inhibition, there by decreasing unnecessary insulin secretion.