Eleven phenols including two chlorophenols, eight alkylphenols and bisphenol A were derivatized with isobutylchloroformate to form their isobutoxycarbonyl derivatives. Standard phenol mixture was concentrated for the isobutoxycarbonyl (isoBOC) derivatization and analysed by gas chromatography/mass spectrometry (GC/MS). The recoveries of the derivatization method of alkylphenols, chlorophenols, and bisphenol A were calculated by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison; shaking and heating method. The linear detector responses were obtained in the concentration range of 5~400ng, with correlation coefficients varying from 0.9755~0.9981. Recoveries of the a1kylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison; the US-EPA method and the isoBOC derivatization method. EJeven phenols jn water samples were extracted with dichloromethane and then concentrated. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode, The recoveries were 85.1~109.9% and 90.3~126.6% for the US-EPA method and the isoBOC derivatization method, respectively. The method detection limits of bisphenol A for SIM were 0.732μg/l and 0.002μg/l for the two methods above, respectively.