The effects of Okcheonsan powder on the body weights, the organ weights, the blood glucose level, the lipid and protein concentrations of serum and liver in diabetic rats were studied. Female rats (Sprague-Dawley, mean weight 313.6$pm$18.5 g) were randomly assigned to one normal and two diabetic groups. They were fed experimental diets for 5 weeks. The diabetic groups were divided into the diabetic control (D-control group) and 3% Ok-cheonsan groups (D-Okcheonsan group). Rats were injected with streptozotocin intraperitoneally to induce diabetes. The body weights, the concentrations of total lipid and triglyceride of liver, the concentrations of total protein and albumin of serum in tole D-control and the D-Okcheonsan groups were significantly decreased compared with those in the normal group. The pancreatic weight in the D-control group was significantly more increased than that in the D-Okcheonsan group, but in the D-Okcheonsan group it was similar to that in the normal group. The fasting blood glucose levels and the atherogenic index in all the diabetic groups were significantly higher than those in the normal group. The concentrations of triglyceride, total cholesterol and LDL-cholesterol of serum, and the cholesterol of fiver in the D-Okcheonsan group were significantly lower than those in the D-control group. The concentration of HDL-cholesterol and HDL-cholestrol/total cholesterol ratio of serum were similar to those in all the groups. The concentrations of phospholipid of serum and liver in the D-Okcheonsan group were significantly decreased compared with those of the normal group, In conclusion, the Okcheonsan powder feeding could decrease the pancreatic weight, the concentrations of the triglyceride, the total cholesterol and LDL-cholesterol of serum, and the cholesterol of liver in the diabetic rats. But the concentrations of the blood glucose, the hepatic triglyceride and the atherogenic index seems to be not affected by it.