Abstract: Isochlorogenic acid A was separated and purified from Artemisiae argyi folium by preparative high-speed counter- current chromatography( HSCCC) using a weak polarity solvent system consisting of n- hexaneethyl acetate- ethanol- water( 3∶ 7∶ 4∶ 6,v / v / v / v),the upper phase acted as stationary phase and the lower phase served as mobile phase.The separation process was performed at a flow rate of 2 m L / min,the rotation rate of the apparatus was set at 900 r / min,and the effluents were detected at 280 nm,a total of 11 mg of target compound was obtained in one step separation from 25 mg of crude extract.The results from HPLC analysis showed that the compound with 99.01% purity and the chemical structure was characterized as Isochlorogenic A by high performance liquid chromatography- mass spectrum( LCMS- IT- TOF) and Nuclear Magnetic Resonance Spectroscopy(1H- NMR).It showed that preparative high- speed counter- current chromatography could separate and purify Isochlorogenic acid A successfully from Artemisiae argyi folium. The method was of high separation efficiency,and great importance for isochlorogenic acid A applications in the food and medical fields.