Abstract:Eighty-eight strains of endophytic fungus,belonging to 28 genera, were isolated from wild Polygala tenuifolia Willd of two different growth stage,and the inhibitory activities screening to three species of microbe were conducted research. The results showed that the quantity, population and distribution of the endophytic fungi varied in different tissue and different growth stage of P. tenuifolia. The species of endophytic fungus distributed in stem were more than in root and leaf, and the dominant genus was Alternaria Nees. Seventy-three strains, accounting for 83.0% of all the isolates, presented antimicrobial activities to the tested indicators. High antimicrobial activities were found in four strains, which seperatedly belonged to the genera as follows: Trichothecium Link,Cephalosp-orium Corda,Alternaria Nees,Trichosporiella Kamyschko. et al.