The present study was designed to compare the effect of soybean oils and corn oils on serum levels of total cholesterol, HDL-cholesterol and free cholesterol in cholesterol-fed rats. The results are as fellows: 1. The average body weight gain in soybean oil diet group was lower than that of the control group. 2. The food efficiency ratio in soybean oil diet group was lower than corn oil diet group. 3. The serum levels of total cholesterol in soybean oil diet group than that in corn oil diet group. 4. The serum levels of free cholesterol in soybean oil diet group was lower than that in corn oil diet group. 5. The serum levels of HDL-cholesterol in soybean oil diet group than that in corn oil diet group. 6. The serum levels of VLDL-, LFL-cholesterol in soybean oil diet group was lower than that in corn oil diet group.