Abstract: Wild Paeonia delavayi from 8 altitude gradients in Lijiang, Yunnan Province. Root, stem, and leaf tissues were collected for isolation, cultivation and ITS identification of endophytic fungi. The community structure diversity of endophytic fungi and their relationships with environmental factors were analyzed. Results showed that a total of 333 endophytic fungi were isolated, including 82 from roots, 115 from stems, and 136 from leaves. The dominant genera were Penicillium, Aspergillus, Clonostachys, and Trichoderma, with isolation frequencies of 22.82%, 11.41%, 10.81%, and 10.51%, respectively. Root-associated fungal communities exhibited high richness and prominent dominance of certain genera, while leaf-associated communities displayed high diversity with relatively even distribution. The type and strain number of endophytic fungi in each organizations showed a gradually decreasing trend with increasing altitude, meanwhile, the endophytic fungal diversity and richness decreased, while their dominance increased with increasing altitude. Significant differences in endophytic fungal community structures were showed between plots above and below an altitude of 3000 meters, and the similarity in community structure was higher in plots above 3000 meters. Diversity indices and dominant genera were related to environmental factors, altitude, hydrolyzable nitrogen, total nitrogen, and organic matter were important factors that affected the composition of endophytic fungal communities. Environmental differences among different altitude gradients (especially soil nutrient conditions) were the primary factors affecting the community composition and diversity of endophytic fungi in wild P. delavayi populations in Lijiang, Yunnan.