The present investigation was carried out to study the effect of rice bran oil (RBO) on hypocholesterolemic activity of experimental rats, and also the effect of feeding with rice bran oil (RBO) and blend oil on the growth and lipid parameters of the serum and liver of rats. Fatty acids composition and unsaponifiable matter of rice bran oil and blend oil were determined, Results showed that, rice bran oil had a higher content of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA) than that of blend oil. Rice bran oil contained relatively higher concentration of compesterol, stigmasterol, b-sitoisterol, cycloartanol, cycloartenol 24-Methylenecy cloartanol and oryzanol compared to the blend oil. The serum total and LDL-cholesterol level of rats that maintained on rice bran oil diet was significantly lower than those fed on blend oil diet. HDL-cholesterol showed a tendency to be higher. Liver lipids of rats fed on rice bran oil were also markedly lower than their blend oil fed counterparts. Finally, it can be concluded that, using rice bran oil had the pronounced effects for lowering cholesterol levels of the blood in experimental rats. The cholesterol lowering ability of rice bran oil appears to be due to unsaponifiable matter  and a higher content of polyunsaturated fatty acids.