Abstract: To determine seven phenolic compounds (phenol, o, m, p-cresol, o, m, p-dihydroxybenzene) in mainstream cigarette smoke accurately, a method was established by adopting N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) silanization-GC/MS. The total particulate matters in mainstream smoke of two cigarettes were trapped by Cambridge filter pad under standard ISO smoking condition and extracted ultrasonically with chloroform for 10 min after adding internal standard (Phenol-d₅). One mL extract was added to 30 μL MSTFA, followed by separation on a capillary column EIite-624 and analyzed by GC/MS after derivation for 20 min at 60 ℃. The results showed that: 1) The relative standard deviations (RSDs), recoveries and limits of quantitation (LOQs) of this method were 2.6%-5.6%, 93.1%-102.9% and 0.005-0.026 μg/cig, respectively. 2) Comparing with the standard method, m-cresol and p-cresol were completely separated by this method, which could determine the seven phenolic compounds in mainstream cigarette smoke accurately. 3) The data of 27 cigarette samples determined by the established method agreed well with those obtained by the standard method. This new method is stable, accurate, precise and of good repeatability, it is suitable for determining the seven phenolic compounds in mainstream cigarette smoke.