The endophytic and epiphytic fungi from the leaves of Pteroceltis tatarinowii were studied to understand the composition and evolutionary relationship of endophytic and epiphytic fungal communities on this ancient and peculiar plant. This study provides valuable information about fungal resource conservation and an improved understanding of mutual evolutionary relationships between endophytic and epiphytic fungi and their host plants. Additionally, a rich and sizeable collection of endophytic and epiphytic fungi from this specific plant may provide a unique source of bioactive compounds associated with P. tatarinowii. Healthy plant samples were collected from natural distribution areas of P. tatarinowii in Langyashan Natural Reserve, Anhui Province. A total of 2696 isolates of endophytic fungi (839 strains) and epiphytic fungi (1875 strains) were identified and classified into 43 genera, 5 families, and 4 orders. Both species richness and fungal isolation frequency were significantly higher for epiphytic fungi than for endophytic fungi. The dominant order of endophytic (90.23%) and epiphytic fungi (92.51%) was Moniliales. Dematiaceae and Moniliaceae were the dominant families of both endophytic fungi, representing 47.56% and 42.67% of isolates, respectively, and epiphytic fungi, representing 67.04% and 25.47% of isolates, respectively. The dominant genera of endophytic fungi were Periconia (31.47%) and Penicillium (10.73%). Glomerularia (20.03%), Gonatobotrys (13.95%), and Penicillium (12.22%) were the dominant genera of epiphytic fungi. Twenty-three common genera of endophytic and epiphytic fungi were isolated from leaves of P. tatarinowii, accounting for 53.49% of isolates: Penicillium, Aspergillus, Geotrichum, Gonatobotrys, Streptomyces, Glomerularia, Paecilomyces, Oidiodendron, Trichoderma, Alternaria, Torula, Periconia, Clasterosporium, Phragmocephala, Endophragmia, Stigmella, Acaulopage, Spiromyces, Syncephalastrum, Choanephora, Phomopsis, Gloeosporium, and Marssonina. Six genera (19 strains, 0.70%; Oedocephalum, Gilmaniella, Pithomyces, Trichaegum, Colletotrichum, and Sphaceloma) were unique to endophytic fungi, and 14 genera (120 strains, 4.45%; Candida, Botrytis, Tritirachium, Trichothecium, Thallospora, Basidiobotrys, Chaetopsis, Bipolaris, Menispora, Cordana, Polythrincium, Cochlonema, Mycotypha, and Stylopage) were unique to epiphytic fungi. Differences in the composition of endophytic and epiphytic fungi existed at different sampling locations. Periconia (20.5%), Penicillium (5.24%), Trichoderma (8.70%), and Streptomyces (5.13%) were the dominant genera of endophytic fungi from the sunward-facing sample leaves, whereas, the dominant genera of epiphytic fungi were Glomerularia (20.03%), Penicillium (11.74%), Periconia (6.84%), and Gonatobotrys (5.65%). The dominant genera of endophytic fungi from the shade sample leaves included Periconia (11.08%), Penicillium (5.48%), and Oidiodendron (6.20%), whereas the dominant genus of epiphytic fungi was Gonatobotrys (6.57%). Periconia was the dominant genus of endophytic fungi isolated from the upper (17.76%) and lower (13.59%) leaves. Penicillium was the dominant genus of epiphytic fungi isolated from the upper (8.94%) and lower (5.01%) leaves. The Shannon-Wiener diversity index (H'=2.44) and Margalef richness index (R=2.88) of endophytic fungi were less than that of epiphytic fungi (H'=2.57, R=3.32). The endophytic and epiphytic fungal communities of P. tatarinowii had a similarity coefficient of 0.70. Fisher's exact test analysis suggested that there was no significant difference (P=0.072) between the composition of endophytic and epiphytic fungi from the foliage of P. tatarinowii.