Abstract: A method for the simultaneous detection of several chlorinated acid herbicides such as dicamba and bentazon etc by ion-pair chromatography was developed. Several strongly polar and weak reserve chlorinated acid herbicides can be separated simultaneously from reversed-phase chromatography column by adding ion-pair reagent. Shim-pack VP-ODS column was used for analyte separation with ion-pair solution and the mobile phase was at a constant flow rate of 1.8 mL/min. Extraction condition, ion-pair and the mobile phase were selected and optimized. The detection limit ranges of the method for different herbicides were 0.03 to 0.15 μg/L with RSD less than 10%. Comparing with high performance liquid chromatography and gas chromatography-mass spectrometry, the established method completely separates the 9 sorts of herbicides with advantages of simple operation, high separating effect, high recoveries and less interferences, which meet the requirements of all kind of water.