A method was established for the separation and determination of chlorinated paraffin（CPs） and polychlorinated biphenyls（PCBs） in sediment.CPs and PCBs were firstly extracted with dichloromethane from sediment，then CPs were separated from PCB via a cleanup procedure with complex Florisil/Silica column.The fraction containing PCBs was eluted with 80 mL hexane，followed by the elution of fraction containing CPs with 60 mL dichloromethane.CPs were determined by GC-ECNCI-LRMS under selective ion monitoring mode and PCBs were analyzed by GC-EI-MS，and quantified by the internal standard method.The procedure of sample pretreatment，amount of dispersant and instrument conditions were also optimized.The result indicated that recoveries of technical mixture of CP52 and 22 PCB standards in spiked matrix ranged from 86% to 99%，with RSDs less than 10%.The method detection limits for short-chain chlorinated paraffin（SCCPs） and medium-chain chlorinated paraffin（MCCPs） were in the ranges of 0.144-3.47 ng/g and 0.530-2.24 ng/g，respectively.The method was applied in the determination of CPs and PCBs in six sediments from Dongjiang River.The concentrations of SCCPs，MCCPs and PCBs were in the ranges of 0.245-1.58 μg/g，0.538-1.83 μg/g and 1-100 ng/g，respectively.Therefore,the method was rapid，sensitive and accurate，and was suitable for the reliable investigation of CPs and PCBs in sediment as well as in soil samples.