Abstract: The organic pollutants of α-HCH, β-HCH, γ-HCH, δ-HCH, p,p'-DDE, p,p'-DDD, o,p'-DDT, p,p'-DDT, hexachlorobenzene, benzopyrene in groundwater samples were quantitatively determined by gas chromatography (GC) and high performance liquid chromatography (HPLC). And gas chromatography-mass spectrometry (GC-MS) was also used for the identification of organic pollutants in the samples with complex matrix, especially for the confirmation of the components with high concentration in the samples and also for the judgement of false-positive results. The analytical results indicate that GC-MS plays a very important role in analysis of organic pollutants in groundwater samples.