In this paper,an analytical method was developed for the analysis of benzoic acid and sorbic acid by reversed phase chromatography with imidazolium ionic liquid as mobile phase additive.Effects of imidazolium ionic liquid type and concentration,methanol concentration and ultraviolet detection wavelength on the separation and detection of benzoic acid and sorbic acid were investigated,and the retention rules of the two analytes were discussed.The separation and detection of benzoic acid and sorbic acid were achieved in 7.0 min,with an Agilent ZORBAX ODS reversed phase column using methanol-0.2 mmol/L 1-butyl 3-methylimidazolium chloride aqueous solution(40∶60,by volume) as mobile phase at an ultraviolet wavelength of 230 nm,a flow rate of 1.0 mL/min and a column temperature of 35 ℃.The linear ranges for benzoic acid and sorbic acid ranged from 1.0 mg/L to 100.0 mg/L,with correlation coefficients(r) more than 0999 5.The detection limits for two analytes were both 0.02 mg/L.The method was applied in the determination of benzoic acid and sorbic acid in beverage samples.The spiked recoveries were in the range of 93.9%-104% with relative standard deviations(RSD) not more than 4.0%,which could meet the requirements for quantitative analysis.