Abstract: The analytical method of dichlorodimethyl sulfide (HS) and its hydrolysis prod-uct-thiodigycol (TDG) in the contaminated soil samples were established by gas chromatog-raphy-mass spectrometry (GC/MS). The HS and TDG were extracted with dichlorometh-ane and sub-boiling water, respectively. The recovery ratio in the soil was 89. 4% and 93. 2% , the relative standard deviation was 4. 18 % and 4. 32%, respectively. The concentrations of HS and TDG in the contaminated soil samples were 0. 38 - 0. 48 μg/g and 3. 04-3. 88 μg/g. The detection limits of HS and TDG were 0. 004 μg/g and 0. 020 μg/g (3σ,n= 5), respectively. GC/MS was performed to determine HS and TDG in the poisonous soil. The characteristics of the molecular ion peaks, base peaks and other fragment ions in their were discussed. The analyses results indicate that the method established is convenient, accurate and sensitive.