A gas chromatograph-mass spectrometric（GC-MS） method based on ultrasound assisted extraction and dispersive solid phase extraction was developed for the simultaneous determination of 18 polychlorinated biphenyls（PCBs） in fresh tea leaves.The samples were extracted using a mixture of hexane-acetone（1∶1,by volume） by ultrasonic extraction,and cleaned up with the mixed sorbents of carboxylated multi walled carbon nanotubes（MWCNTs-COOH） and primary secondary amine（PSA） after replacing hexane-acetone by toluene,then detected by GC-MS under selected ion monitoring mode.The PCBs were qualitatively confirmed by retention time and relative abundance ratio of characteristic ions,and quantified by the external standard method with matrix matched standards solution.The chromatographic and MS parameters influencing separation and sensitivity were optimized,and several important factors affecting extraction and purification efficiency such as type and volume of extraction solvent,extraction time,type and amount of cleanup sorbent and cleanup time were investigated.Under the optimum conditions,satisfactory linear relationships for the analytes were observed in the concentration range of 5-500 μg/kg with correlation coefficients not less than 0.999 8.The recoveries for 18 PCBs in fresh tea leaves at spiked levels of 5,10 and 100 μg/kg were in the range of 92.3%-111% with relative standard deviations（n=6） of 1.2%-7.9%.The limits of detection and the limits of quantitation for PCBs were 0.5-1.4 μg/kg and 5 μg/kg,respectively.The method was simple,rapid,accurate,sensitive and effective in purification,and was suitable for the determination of 18 PCBs in fresh tea leaves.