A chemiluminescence(CL)-high performance liquid chromatography (HPLC) system, where CL detector was equipped with normal phase HPLC, was used in order to specifically detect lipid hydroperoxide in the heart of doxorubicin (DXR) administered mice. Luminol and cytochrome c were used as the luminescence reagents specific for the hydroperoxide. Phosphatidylcholine hydroperoxide was detected in the heart, indicating participation of lipid peroxidation in the DXR-induced cardiotoxicity. This system is of great use to study the DXR-induced lipid peroxidation in vivo.