We evaluated the inhibition of low-density lipoprotein (LDL) oxidation inhibition by a hot water-soluble extract of Saururus chinensis Bail (HWSCB) in vitro and the lipid-lowering effects of HWSCB in rats fed high fat diet (HFD). HFDs were supplemented with 5% HWSCB (HFSCB5 group), 10% HWSCB (HFSCB10 group), or 1% tannic acid (Tannin group). The Tannin group served as a positive control for the study, based on tannic acid's known lipid-lowering effect and water-soluble characteristics. LDL oxidation was dose-dependently inhibited in the presence of HWSCB, and the effect of HWSCB was comparable to that of vitamin C. Significant reductions in triglyceride (P < .05) and cholesterol (P < .05) levels in the plasma and liver of the HFSCB5, HFSCB10, and Tannin groups were observed. High-density lipoprotein cholesterol was elevated (P < .05), but LDL was decreased in a dose-dependent manner for the HFSCB samples. These results were associated with a significant decrease in the atherogenic index for the HFSCB samples, especially for HFSCB10. In addition, fecal excretion of triglyceride with HWSCB supplementation was greater than with tannic acid supplementation. The findings of this study suggest that HWSCB may reduce plasma and hepatic lipids, especially triglyceride, in rats fed high fat diet.