A sensitive and precise method for simultaneous determination of some major cholesterol autoxidation products(COPs)was described. The method was based on high performance liquid chromatography (HPLC) with 6-chlorostigmasterol as internal standard.After saponification and extraction, the COPs were derivatized into benzoates for measurement by HPLC with ultraviolet detection. Each product gave a linear response(r＞0.9990) over a concentration range of 0.312～10.000 mg/L. The intra-and inter-assay co-efficients of variation was 2.15%～5.40% and 1.23%～3 .70%, respectively. This method was successfully applied to the determination of COPs in cholesterol standard reference material and in human serum.