Abstract: A liquid chromatographic method combined with sample pretreatment technology has been developed to accurately determinate the concentration of petroleum sulfonates in oil samples of oilfield produced liquid. Petroleum sulfonates were extracted from oil phase into water phase with several different polar solvents, and the water phase solution was detected by liquid chromatography. The suitable amount oil samples were weighed into the test tube, and n-hexane, dichloromethane, ethanol and distilled water were added in turn. The test tube was shaken thoroughly and stayed for layering. The lower layer solution was used for chromatographic analysis. The anionic exchange column and gradient elution including methanol/water and methanol/saline were used. The results showed that the adopted extraction technology had a high recovery over 90%, and the limit of quantitation and linear range of chromatographic method were 10 mg/L and 10-2000 mg/L, respectively. The developed method herein can be used to analyze the petroleum sulfonates with lower content of in oil samples rapidly and accurately.