In this study,the secondary metabolites of an endophytic Chaetomium sp.L-45 from Dioscorea opposita were isolated and identified.The ethyl acetate extract of the rice fermentation of the fungus were separated by silica gel column chromatography,Sephadex LH-20,semi-preparative High-performance liquid chromatography,etc.,and the chemical structures of the compounds were identified by NMR and HR-ESI-MS analysis.As a result,four compounds were isolated and identified as 3,4-dimethoxy-5-hydroxy-6-propyl-benzoic acid (1),5-isoprenylindole-3-carboxylic acid (2),lecanorin (3),and ergosterol (4).Among them,compound 1 is a new compound,compounds 2 and 3 were isolated from genus Chaetomium for the first time.