Abstract: In order to understand the community structure and distribution of endophytic fungi in the plants of Bidens frondosa, the diversity of endophytic fungi was analyzed by sampling, tissue isolation, culture and identification. The results showed that there were abundant endophytic fungi in the plants of Bidens frondosa.There were 19 species in the plants. Among them, there were 17 species in 11 genera of sporulation fungi, all of which are Deuteromycetes fungi and there were 2 species Sporogenous fungi. The dominant endophytic fungi were Colletotrichum sp., Phomopsis sp.1 and Alternaria sp. The distribution of endophytic fungi of Bidens frondosa was widespread, and the total colonization rate was 51.0%. The fungus colonization rate of leaf was higher than that of stem, the fungus colonization rate of young stem was lower than that of old stem, and the fungi colonization rate of endophytic fungi gradually decreased from leaf base to leaf tip. Habitat and tissue types of host plants had important effects on the composition and distribution of endophytic fungi.