To observed the effects of phytosterol ester (PSE) on serum lipid level in rats.(1) Under high-fat fed model, rats were oral administrated either no PSE (model), 4.0, 16.0 or 32.0 mg/kg bw PSE dissolved in oil. After 30 days of this treatment serum was obtained for lipid determination. (2) Ovariectomized rats were randomly assigned to model group, or treated with diethyl stilbestrol (E2, 22.5 microg/kg bw), PSE (32.0 mg/kg bw) or free phytosterol (FPE, 500 mg/kg bw). After fed for 60 days, body weight, liver and uterus weight, serum lipid and estrogen level were measured. In both experiments, another group of normal rats were taken as control.High-fat fed rats administrated with 3 doses of PSE had significantly lower triglyceride (TG) following 30 days of treatment compared to model group. A significant decrease in total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) was observed in 32.0 mg/kg bw PSE group, while a significant increase in high density lipoprotein cholesterol (HDL-C) and ratio of HDL-C/TC was observed in the same group ( P < 0.05). For ovariectomized rats treated with PSE or FPE, a significant lower body and liver weight with lower TC and TG level were observed in comparison with model group (P < 0.05). A little increased uterus weight by PSE and FPE was also observed, though no significant elevation in estrogen was reported.Phytosterol ester have potential to decrease hyperlipidemia.