A method of ion chromatography（IC） with suppressed conductivity detection for the simultaneous determination of F-，Cl-，Br-，NO-3，SO2-4 anions in motor gasoline and diesel oil was established.After ultrasonic extraction with 90% methanol aqueous solution and centrifugation,the sample in aqueous phase was purified with 0.22 μm hybrid filter membrane,and then quantitatively analyzed by the external standard method using IC instrument with 15 mmol/L KOH as the eluent.The effects of concentration and flow rate of the eluent,and concentration of methanol aqueous solution on the detection of five anions were investigated.The linear relation of five anions were good in the range of 0.50-20.00 mg/L and all the linear correlation coefficient were not less than 0.999.The average recoveries of target anions in gasoline were in the range of 87.6%-109.7% with relative standard deviations（RSDs） of 0.4%-3.5%,and the average recoveries of target anions in diesel oil were 86.8%-110.0% with RSDs of 0.1%-2.9%.The limits of detection（LOD） of five anions were in the range of 0.01-0.04 mg/kg.This method avoids the high requirements on the instrument,complicated and time-consuming pretreatment process.It was simple,reliable and sensitive,and was suitable for the simultaneous detection of trace inorganic anions in motor gasoline and diesel oil.