Abstract: The purge-trap gas chromatography-mass spectrometry(GC-MS) is applied to analyze 54 volatile organic compounds (VOCs) including halohydrocarbon, chlorinated benzene and benzene series in soil. The selected ion monitoring (SIM) is adopted for segmental scanning. Compared with full scan, SIM is more effective for multicomponent quantitative analysis of soil. The internal standard method is used to draw calibration curve. The method detection limit is 0.20×10^-9 -1.20×10^-9. The standard addition recovery of substrate is 82.0%-112.5% with the accuracy 0.1-14.5 percentage points higher than that by full scan.