Hyperlipidemia is caused by high dietary intake of cholesterol and saturated fats, and is known as a major risk factor for atherosclerosis. In the oriental medicine, Cheunggansoyo-san (CGSYS) has been used for supplementing hematopoietic function and for treating cardiovascular disorders. In the present study, CGSYS was administered into hyperlipidemic mice. Increases in body weight and cholesterol levels induced by hyperlipidemic diets for 6 weeks were significantly inhibited by CGSYS administration. Serum levels of glucose, triglyceride, SGOT, and SGPT values were all decreased by CGSYS treatment compared with hyperlipidemic dietary mice. Moreover, CGSYS decreased LDL-cholesterol, but increased HDL-cholesterol levels in hyperlipidemic mice. Thus, the present results suggest that CGSYS appears to De effective for down-regulating risk factors of hyperlipidemia.