Abstract: The content of pentachlorophenol in wood was determined by GC. The sample was extracted statically with ethanol at 100 ℃ for 10 min. DB-5 capillary column and electron capture detector were used for separation and determination.Linear relationship between values of peak area and mass concentration of pentachlorophenol was kept in the range of 0.01-50 mg·L-1, with detection limit (3S/N) of 0.01 mg·kg-1. Using sample of wood as matrix, test for recovery was made by standard addition method, and values of recovery obtained were in the range of 94.2%-98.2%, with values of RSD (n=6) less than 4%.