A gas chromatography-ion trap tandem mass spectrometric（GC-IT-MS/MS） method was established for the determination of 25 organochlorine pesticides（OCPs） and polychlorinated biphenyls（PCBs） in soil and sediment.The sample was extracted with hexane and acetone（1∶1，by volume） by accelerated solvent extraction（ASE），cleaned up by solid phase extraction（SPE）.The MS/MS parameters were systematically investigated and optimized.Under the optimal conditions，the linear ranges of 17 OCPs ranged from 1.73 μg/L to 2208 μg/L（except for endrin from 3.45 μg/L to 441.6 μg/L）,with the method detection limits（MDLs）of 0.049-0.274 μg/kg,and the linear ranges of 8 PCBs ranged from 0.87 μg/L to 110.4 μg/L,with the MDLs of 0.028-0.049 μg/kg.The average recoveries of 25 OCPs and PCBs at two spiked concentration levels of 0.345 μg/kg and 3.45 μg/kg were in the range of 70%-108% with relative standard deviations（RSDs） of 5.0%-14.0%.The method was applied in the determination of 25 OCPs and PCBs in complex soil and sediment samples. The results showed that，compared with the GC-MS method，the IT-MS/MS method could effectively eliminate a large number of interference factor，reduce the possibility of false positive and false negative results，and improve the accuracy of quantitative results.