Abstract: Head-space GC was applied to the determination of 25 volatile halogenated hydrocarbons in drinking water. 10.0 mL of water sample were mixed with 3 g of NaCl in a tightly capped head-space bottle and manipulated as described in the procedure. The equilibrium temperature, equilibrium time and injection time for the head space sampler were set at 75 ℃ , 35 min and 0.06 min respectively. DB-1701 capillary chromatographic column (30 m×0.32 mm, 0.25 μm) was used for separation and ECD was used in the determination. Linear relationships between values of peak area and mass concentration of the 25 volatile halogenated hydrocarbons were kept in definite ranges. Detection limits (3S/N) and lower limits of determination (10S/N) found were ranged from 0.002 to 1.3 μg·L-1 and from 0.01 to 4.4 μg·L-1, respectively. Tests for recovery were performed at 3 concentration levels with addition of the mixed standard solution, results of recovery found were in the range of 92.0%-106% with RSD′s (n=6) in the range of 3.0%-6.3%.