A gas chromatography-mass spectrometric(GC-MS) method was established for the simultaneous determination of 42 semivolatile organic compounds,including polycyclic aromatic hydrocarbons(PAHs),polychlorinated biphenyls(PCBs),organochlorine pesticides(OCPs) and organophosphorus pesticides(OPPs)in groundwater.The preparation and analytical conditions,such as solid phase extraction(SPE),liquid-liquid extraction(LLE),extraction solvent and chromatographic column,were optimized.The 42 pollutants in groundwater were extracted by liquid-liquid extraction with ethyl acetate-hexane(1∶4),then determined by gas chromatography-mass spectrometry under selected ion monitoring(GC-MS/SIM) mode.Isotope labled acenaphthene-d10,phenanthrene-d10,chrysene-d12 and perylene-d12 were used as the internal standard for the quantitation analysis.Under the proposed conditions,the calibration curves of the compounds were linear in the range of 0.5-1 000 μg/L with correlation coefficients higher than 0.995.The method detection limits(MDL) were in the range of 0.05-3.08 ng/L.The accuracy and precision of the method were determined by analyzing water samples spiked with three concentration levels of 10,40,400 ng/L target compounds.The recoveries were in the range of 73.0%-107%,with RSDs(n=5) of 1.4%-11.3%.The method is sensitive,accurate and simple,which could significantly improve the efficiency in the analysis of main organic pollutants in groundwater.The method was successfully applied in the analysis of trace organic contaminants in groundwater samples collected from the surrounding area of Shijiazhuang,China.