This study was undertaken to elucidate the role of L-carnitine on cardiotoxicity induced by doxorubicin in mice. We designed to investigate both lipoperoxidation and histopathology in experimental group. The results obtained from prior with concurrent treatment of L-carnitine showed as follows; 1) Combination of L-carnitine showed significant inhibition of lipoperoxide in liver than heart. 2) By means of electron microscopy, we obtained histological evidence that doxorubicin-induced cardiomyopathy, is prevented by L-carnitine.