Abstract: Based on the principle of the reaction of NaOH with pentachlorophenol (PCP) and formation of PCP-Na, waterinsoluble of PCP is transformed into watersoluble salts （PCP-Na） to realize the extraction of PCP from the soils. Ultraviolet spectrophotometric method was adopted to determine PCP at 319 nm. The extraction condition for PCP was optimized with the stirring rate of 300 r/min, extraction solution at pH>12.5, the ratio of soil/liquid=1/8(g/mL) and extraction time of 20 min. The sensitivity of the method is 2 μg/mL for PCP with recovery of 91.2%~108.1%. The method has been applied to the analysis of PCP in farmland soils with advantages of high efficiency and simple operation.