Male Sprageu-Dawely rats fed a cholesterol diet (Control group) or cholesterol diet supplemented with the water-soluble extract of stem bark from Cudrania tricuspidata(CTSB group) at the level of 0.5% for 2 weeks. Concentration of triglyceride in serum of CTSB group was significantly lower than that of control group. However, the other lipids concentrations of liver and serum, body weight gain, and food intake did not show significant difference between CTSB group and control group. Antioxidative activities of water-soluble extract from stem bark of Cudrania tricuspidata on the lipid peroxidation in rat were also studied in vivo by measuring the formation of thiobarbituric acid reactive substance(TBARS). Concentration of TBATS in the liver homogenates of CTSB group was significantly higher than that in control group. Nonheme iron concentration was significantly increased in the liver of CTSB group compared to control group. suggested that enhanced nonheme irom was associated with enhanced peroxidation of liver in CTSB group. These results suggested that water soluble extract from stem bark of Cudrania tricuspidata exert the hypotriglycerolemic effect and might amplify the lipid peroxidation of tissues in cholesterol fed rats.