To investigate the components with antioxidant activity from Citrus aurantium L. var.amara Engl., the Citrus aurantium L. var.amara Engl. alcohol extract was purified by several traditional column chromatography technologies such as silica gel column, dextran gel column and polyamide column, combined with HPLC,NMR and other modern technologies. Three compounds were separated from chloroform and ethyl acetate extract and identified as homoeriodictyol, bergaptol and choerospondin. All of them were first isola...