The chemical constituents of aerial part of Chromolaena odorata were explored by silica gel column chromatography as well as Sephadex LH-20 chromatography and their antifungal activity were also tested.Finally,10 compounds were isolated from the ethyl acetate extract of C. odorata and their structures were determined by various spectral data including ¹H NMR,¹³C NMR and MS.The structures were identified as 5,6,7,4′-tetramethoxyflavanone (1),eriodictyol-7,4′-dimethyl ether (2),5,7-dihydroxy-6,4′-dimethoxyflavanone (3),dihydrokaempferide (4),isosakuranetin (5),4′-hydroxy-5,6,7-trimethoxyflavanone (6),5,6,7,3′,4′-pentamethoxyflavanone (7),3′-hydroxy-5,7,8,4′-tetramethoxyflavone (8),diosmetin (9),kaempferol (10).Among them,compounds 2 and 8 were isolated for the first time from C. odorata.The antifungal activity on 4 pathogenic fungi of Juglans regia of different extracts of C. odorata and column chromatography of different distillates of the ethyl acetate layer extract from C. odorata were measured by growth rate method.It was found that the active components were concentrated in distillate 2 (petroleum ether:acetone=5∶1).The virulence of the compounds 4,5 and 7 against the pathogenic fungi were determined.According to the results compound 5 showed the significant inhibitory effect on the growth of mycelium with EC₅₀ of 0.106 2 mg/mL.The results provide a theoretical basis for the exploitation of plant-derived pesticides by using C. odorata.