An analytical method of hydrophilic interaction chromatography with indirect ultraviolet detection was developed for the determination of tetrabutylphosphorus and tetrabutylammonium using ionic liquids as mobile phase additives.Effects of imidazolium ionic liquids,pyridinium ionic liquids,organic solvents,detection wavelengthes and other factors on the determination of tetrabutylphosphorus and tetrabutylammonium were investigated.The roles of ionic liquids were discussed.The separation and detection of tetrabutylphosphorus and tetrabutylammonium were achieved within 15 min on a hydrophilic interaction chromatographic column at 30 ℃,with acetonitrile-1.0 mmol/L 1-ethyl-3-methylimidazolium tetrafluoroborate(60∶40,by volume) as mobile phase at a flow rate of 1.0 mL/min,and the ultraviolet detection wavelength was set at 210 nm.The limits of detection for the analytes were in the range of 1.0-1.2 mg/L.The linearity and reproducibility of the method were good.The method was applied in the analysis of Songhua River water samples and Keyin River water samples with the spiked recoveries between 95.9% and 107%.This method is simple and easy to use.