Abstract: A method for the simultaneous determination the ethanol washing solution in the synthesis of PPS by capillary column gas chromatography is established. The composition of ethanol washing solution in the synthesis of PPS is ethanol,water,P-dichlorobenzene,N-methy1pyrr0lidone(NMP). All components were separated and identified on a DB-WAX capillary column using a TCD detector. Under the optimized conditions, all of the four washing solution showed good linear relationships with good correlation coeffients(not less than 0.998) in the prescribed concentration range.At three spiked levels,the recoveries for the four components of the ethanol washing solution were 95.72%~118.75% with the relative standard deviations(RSDs) less than 4.91%.The limits of detection(LODs) of the method were 0.51~1.74 mg/kg. The method is simple, rapid and accurate, and is suitable for the simultaneous determination of the ethanol washing solution in the synthesis of PPS.