Two metabolites were isolated as metabolic products of 2-methyl-3-o-tolyl-4 (3H)-quinazolinone (MTQ) in the 9000×g supernatant fraction of rabbits liver. These products were identified as 2-methyl-3-o-hydroxymethylphenyl-4 (3H)-quinazolinone (MHQ) and 2-methyl-3-o-tolyl-4 (3H)-quinazolinone N-oxide (MTQNO) by compairing with authentic samples. Ultraviolet absorption spectra, fluorescence spectra, paper chromatography and thin-layer chromatography with seven kinds of solvent system and paper electro-phoresis were employed for the identification.