Objective : This study was undertaken to investigate how Bombycis corpus (BC) effects the development and progress of complications occurring in Diabetes Mellitus (DM). Methods : Laboratory rats were seperated into three groups; normal, rats with DM and treated with BC, and rats with DM and not treated. In this study DM was experimentally induced through injection of streptozotocin. The BC treated group was given BC extract p.o. for 15 days. Then, The activities of glucose phosphatic enzymes and polyol pathway channels were observed. Results : The blood glucose level greatly increased in the DM groups after injection of streptoztocin, but it significantly decreased in the BC treated group. Significantly enhanced levels of serum insulin levels were seen in the BC treated group, while supressed levels were seen in the untreated DM group. Weight was recovered by the BC treated group, matching the normal group. Decreased enzyme activity of aldose reductase, sorbitol dehydrogenase and glucose-6-phosphatase were seen in BC treated diabetic rats. Increased enzyme activity, of the glucokinase and hexokinase were seen in BC treated diabetic rats. Conclusions : This study suggests that BC normalized the blood glucose and serum insulin levels destablized by DM. Because increased activity of glucose phosphatic enzymes, glucokinase and hexokinase, and decreased glucose-6-phosphatase activity, and suppression of polyol pathway enzymes, aldose reductase and sorbitol dehydrogenase, were all seen, these observations suggest that BC suppresses blood glucose levels and prevents complications due to DM.