For the simultaneous metabolic profiling analysis of catecholamines and polyamines in a single run, catecholamines and polyamines were first converted to (N,O)-ethoxycarbonyl (EOC) derivatives in two-phase solution with two-step pH adjustment.And the resulting EOC derivatives were recovered by solvent extraction with subsequent pentafluoropropionyl derivatization of the remaining active hydrogens for the analysis by gas chromatography-mass spectrometry in selected ion monitoring mode.This method was linear (r ≥ 0.995) with good precision and accuracy for assay of the catecholamines and polyamines investigated.Its applications to urine specimens from breast cancer patients before-and aFTer-mastectomy will be discussed as compared with those from normal control.