Abstract: A method for the determination of 25 volatile organic compounds, including halohydrocarbons, benzene series, chlorobenzene and etc., by purge and trap-GC/MS in groundwater samples from China Groundwater Survey Project was developed. The detection limits of the method for VOCs were in the range of 0.1~0.4 μg/L and the recoveries were between 88.8%~112.0% with precision of 1.73%~5.53% (n=7). The correlation coefficients of the calibration curve equations for the analytes were better than 0.9995. A quality control procedure for semi-volatile organic compound analysis in groundwater was also proposed. The method provides the advantages of high sensitivity, high accuracy and precision, simple operation and is suitable for batch analysis.