Abstract: GC-MS was applied to the determination of 24 volatile organic compounds (VOC′s) in water. The equilibrium temperature and time of head space were selected at 60 ℃ for 15 min. The analyte were separated on Rtx-1MS column. EI source was used in MS. Linear relationships between values of peak area and mass concentration of 24 VOC′s were kept in the range of 2.5-20 μg·L-1. Detection limits (3s/k) found were ranged from 0.02 to 0.94 μg·L-1. Tests for recovery were performed by addition of mixed standard of 24 VOC′s at 3 concentration levels, results of recovery found were in the range of 75.3%-105.0% with RSD′s (n=7) in the range of 3.2%-12.6%.