Objective To estahlish a solicl phase extraction/capillary gas chromatography ( SPE-GC) method t。 determine phorate and its metabolite phorate sulfone residue in leek. Methods After being extractecl by acetonitrile, samples were further extracted and purified by C18 and PC/NH2 solid-phase extraction columns and then detected by capillary gas chromatography with DB-1701 column. Results As 0. 03 , 0. 30, 0. 90 and 3. 00 mg/kg of both phorate and phorate sulfone being added to samples, average recoveries of phorate ranged from 86. 7% t0 93. 2% , and its coefficients of variation ranged from 2. 46% t0 4. 76%. Average recoveries of phorate sulfone ranged from 85. 9% t0 92. 5% and its coefficients of variation ranged from 2. 82% t0 4. 31% . The limit of detection of the method was 0. 01 m~kg and the limit of quantitation was 0. 01 ng. Conclusion The ruethod is rapid, accurate, sensitive and low in determination limit, thus applicable in the detection of phorate and phorate sulfone in leek.