The effects of Cordyceps militaris on the weight gain, the food intake, the food efficient ratio, and the lipid concentrations of serum, liver, pancreas, heart and aorta in male rats fed cholesterol diet were studied. Male Sprague-Dawley rats were received 4 types of diets for 4 weeks, respectively : a normal diet(without cholesterol), a control diet(hypercholesterolemic diet), a hypercholesterolemic diet supplemented with 3% fruiting body of Cordyceps militaris(CF), a hypercholesterolemic diet supplemented with 3% mycelium of Cordyceps militaris(CM). The body weight gain of rats fed the control diet were significantly increased compared to those of the rats fed diets with CF or CM. But, the hepatic and pancreatic weights of rats fed diets with CF or CM were heavier than those of rats fed the normal diet. In serum of rats fed the CM diet, the concentrations of total cholesterol, triglyceride, LDL-cholesterol and the atherogenic index were significantly lower than those of rats fed the control diet. Also, serum HDL-cholesterol concentration and HDL-cholesterol/total cholesterol ratio were significantly lower in rats fed the control, CF or CM diets than those in rats fed the normal diet. Whereas, the hepatic concentrations of the total lipid, the total cholesterol and the triglyceride were significantly higher in rats fed 3 hypercholesterolemic diets than those in the rats fed normal diet. The heart and pancreatic concentrations of total cholesterol were the highest in the rats fed diet with the CR among rats fed experimental diets. In conclusion, the CM feeding decreased the concentrations of the cholesterol, triglyceride, and LDL-cholesterol and the atherogenic index in the serum of the rats. But the CF or CM feeding could not decrease the hepatic concentrations of the total lipid, cholesterol, triglyceride in the rats fed hypercholesterolemic diets. (Korean J Nutrition 34(3) : 265∼270, 2001)