The effects of the water extract from the stem bark of Acanthopanax senticosus were evaluated on hyperlipidemic rats induced by lipid rich diet or poloxamer-407. The water extracts, when administered orally for 3 consecutive days in hyperlipidemic rats induced by poloxamer-407 (1 ml of 30%), was found to cause a significant decrease in plasma cholesterol and triglyceride concentrations. The water extracts, when treated orally for 5 consecutive days also showed a significant inhibition of serum total cholesterol and triglyceride level in rats treated with lipid rich diet (15% cholesterol, 1% sodium cholate and 84% com oil). HDL-cholesterol, however, was increased significantly.