The hypolipidemic actions of oils reflect their quality and safety for human health. So, the aim of the present study is to test the lipidemic effects of two oil supplements. Experimental mice were fed on normal diet and foods enriched in corn oil or fish oil for one month. Lipid profiles were measured and gene expression of PPAR-α and fatty acid synthase were semi-quantitated using RT-PCR analysis. Results showed significant increase in lipid profiles in corn oil fed group. LDL-c and blood glucose were decreased while HDL-c was significantly increased in fish oil fed group compared to mice fed normal diet. FAS mRNA expression was higher in corn oil fed group while PPAR- was high in fish oil fed group. In conclusion, dietary supplementation of fish oil alters lipid profiles and expression of lipid metabolizing enzymes. Further studies are needed to examine safety of fish oil under high supplemental condition.