Abstract: With the adoption of ECD detector and PLOT column filled with styrene-divinylbenzene porous copolymer, the trihalomethanes and carbon tetrachloride in drinking water were separated and determined by GC through direct aqueous injection. This method had a good effect of separation, without the bad influence of a large amount of water to the determination. The linearity range of trichloromethane was 10-500 μg·L-1, with detection limit of 2.1 μg·L-1. The linearity ranges of carbon tetrachloride and other trihalomethanes were 1-50 μg·L-1, with detection limits in the range of 0.2-0.7 μg·L-1. Recovery rates obtained by standard addition method were in the range of 90.0%-106%, and RSDs (n=7) were in the range of 2.9%-12%. The method was used to analyze water sample, giving results in consistent with those obtained by headspace-GC and the testing time one hour shorter than headspace-GC.