A high performance liquid chromatography with indirect ultraviolet detection was developed for the determination of pyrrolidinium ionic liquid cations by using reversed phase C18 column and UV detector.As an additive of mobile phase,imidazolium ionic liquid is not only a background ultraviolet absorption reagent,but also an effective component for improving the separation of the analytes.The addition of the ion pairing reagent sodium heptanesulfonate to the mobile phase could better improve the separation of cations in the pyrrolidinium ionic liquid.Under the optimal chromatographic conditions,the three pyrrolidinium ionic liquid cations(［MEPy］+,［MPPy］+ and ［MBPy］+) could be effectively separated and detected within 13 min.The linear ranges for ［MEPy］+,［MPPy］+ and ［MBPy］+ were 0.6-100 mg/L,1.3-230 mg/L and 3.6-250 mg/L,respectively,with their correlation coefficients(r) more than 0.999.The detection limits for three analytes were 0.2,0.4,1.1 mg/L,respectively.The method was applied in the detection of homologue pyrrolidinium ionic liquid samples synthesized in laboratory with spiked recoveries of 92.2%-96.7%.The method is accurate and reliable,and is suitable for the separation and detection of pyrrolidinium ionic liquid cations.