Objectives : This study aimed to evaluate the anti-diabetic effect of Wen-Pi-Tang-Hab-Wu-Ling-San (WHW) extract in streptozotocin(STZ)-induced type-1 diabetic rats. Methods : Experimental diabetes were induced by intraperitoneal injection of streptozotocin (60 mg/kg). Two groups of STZ-induced diabetic rats were given the following treatments for 2 weeks by oral Administrations : (1) WHW 10 mg/kg, (2) WHW 100 mg/kg. In addition, vehicle-treated diabetic and nondiabetic controls were used in the experiment. The effects of WHW extract on STZ-induced diabetes were observed by measuring the changes of body weights and the levels of fasting blood glucose, insulin, urea nitrogen (BUN) and creatinine level in sera of rats, respectively. Results : In comparison control group, WHW-treated groups (100 mg/kg) were significantly decreased fasting blood glucose levels and increased serum insulin levels in STZ-induced diabetic rats. Moreover, WHW-treated groups (100 mg/kg) were reduced s-creatinie levels in STZ-induced diabetic rats. In addition, the changes related to diabetic nephropathy with body weight were significantly lower in WHW extract-dosing groups than in the diabetic control. Conclusions : The study thus showed that WHW extract enhanced the anti-diabetic effect in STZ-induced diabetic rats by improving the hypoglycemia. It also increased pancreatic insulin content in these rats.