Objectives: Indongdeungjikolpi-tang(IJT) is used as a traditional treatment of diabetes in oriental clinincs. This study aimed to evaluate the anti-diabetic effect of Indongdeungjikolpi-tang(IJT) in streptozotocin(STZ)-induced diabetic rats. Methods: Diabetes was induced by intraperitoneal injection of streptozotocin(STZ; 60 mg/kg BW) to Sprague-Dawley male rats. Experimental animals(six per group), were treated by oral administration of IJT(100 and 500 mg/kg BW) and glibendimide(3 mg/kg), a known antidiabetic drug for comparison, during 4 weeks. We measured the levels of glucose, insuline, triglyceride, creatinine and urea in sera of each group. An oral glucose tolerance test(OGTT) was also performed in all groups. Results: IJT(100 and 500 mg/kg) significantly reduced blood glucose levels and increased plasma insulin levels in STZ-induced diabetic rats. IJT also significantly reduced the plasma levels of tryglyceride, creatinine and urea in STZ-induced diabetic rats. The OGTT results showed a significant improvement in glucose tolerance in IJT-administrated rats. Conclusions: These data indicate that IJT may improve glocose homeostasis in STZ-induced diabetes, which could be associated with stimulation of insulin secretion.