The effect of dietary intake of marine oils (CLO and SBO) on the lipids, alpha-tocopherol and TBARS in serum and liver was investigated in rats. In the dietary fats (8% in diet), the proportion of marine oils and corn oil was changed at five steps from 100:0 to 0:100. In the groups fed more than 50% CLO, serum cholesterol levels decreased while liver cholesterol increased as compared with the rats fed less than 50% CLO. On the other hand, SBO intake lowered serum cholesterol, TGs and PLs in the group on more than 25% of total fats, while it also induced an elevation of liver cholesterol and total lipids, in slightly higher degree as compared with the case for CLO intake. TBARS levels increased in liver with increasing intake of both marine oils, whereas alpha-tocopherol levels contrarily decreased in serum and liver. Only 0.6 and 0.3% of omega-3 type unsaturated fatty acids (EPA and DHA) were involved in the experimental diets of 50% and 25% marine oil groups respectively, since both marine oils contained about 15% of omega-3 type polyunsaturated fatty acids. Our results show that such a low content of omega-3 type fatty acids affects body lipid metabolism with respect to change in cholesterol, TGs, PLs, alpha-tocopherol and lipid peroxidation.