Shengmai San (SMS), which is comprised of the medicinal herbs of Panax ginseng C.A. Meyer, Schisandra chinensis Baill., and Ophiopogon japonicus Ker-Gawl (2:1:2)., is a traditional Chinese medicine being used for treating coronary heart disease. The aim of this study was to investigate the effects of SMS on the plasma and liver lipids, lipid peroxidation and antioxidant systems in liver and heart of cholesterol-fed rats. Rats were fed on a high-cholesterol (0.5%) diet (control group), high-cholesterol diet containing 2% SMS (2% SMS group) and 4% SMS (4% SMS group) for four weeks. The oxidative stress marker (thiobarbituric acid reactive substances, TBARS) and antioxidant defense systems including glutathione (GSH), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities in rat liver and heart were evaluated. Results showed that rats fed with SMS-containing diet had reduced the H(2)O(2)-induced erythrocytes susceptibility to hemolysis, and 4% SMS feeding rats had higher plasma GSH concentration compared to the animals fed with the control diet. However, SMS had no effect on plasma lipids (total cholesterol, triglyceride and high-density lipoprotein cholesterol) and TBARS concentration. On the other hand, rats fed with the 4% SMS diet reduced the hepatic cholesterol and triglyceride contents. Fecal bile acid excretion was significantly increased in rats fed with the SMS-containing diet. Higher hepatic GSH and lower TBARS concentrations were observed in rats fed with the 4% SMS diet compared with the rats fed with the control diet. No significant difference in activities of GSH-Px, GST and SOD was found in liver and heart after the SMS treatment. Results from this study indicate that the SMS may reduce hepatic lipids and lipid peroxidation in rats.