Plant endophytic microorganisms have a close metabolic relationship with its host plants. Endophytic fungi in leaves of Apocynum venetum was used as research material. Endophytic fungi with the capability of producing flavonoids were screened with the methods of chemical colorimetry and thin layer chromatography, and then they were identificated by observing their morphological characteristics. The results showed that two fungal strains named P-1 and P-2 were screened out. They were detected to be able to produce flavonoid compounds. Strain P-1 belongs to Fusarium ,whereas strain P-2 belongs to Penicillin pinophilum . This study laid a foundation for further exploitation of the endophytic fungi in A.venetum .