This study was designed to observe the effects of the fish oil and some seed oils on the improvement of the lipid composition in rats. In order to induce the triglyceridemia in the rats of the Sprague-Dawley, 12% coconut oil and 3％ each of olive oil, lard, fish oil, perilla oil, corn oil, red pepper seed oil and evening primrose oil were administered to the rats for tweets. Total cholesterol concentrations of serum were lower in the fish oil, perilla oil and corn oil groups and by for higher in the red pepper seed oil and evening primrose oil groups than in the olive oil group(control group). HDL-cholesterol concentrations were a little higher in the red pepper oil and evening primrose oil groups. In the ratio of HDL-cholesterol concentrations to total cholesterol concentrations, all groups were higher percentage than the control group. Cholesteryl ester concentrations of serum were high in n-6 PUFA rich red pepper seed oil and evening primrose oil group. In the ratio of cholesteryl ester concentrations to total cholesterol, all groups(70.0~74.4%)were higher than the control group(62％). Phospholipid concentrations of serum were low in the fish oil and perilla oil groups and triglyceride concentrations were remarkably lower in the fish oil and evening primrose oil groups than in the control group. LCAT activities of serum were higher in the lard group than in the control group, but lower in the other groups.