Abstract: Epiphytes are important and special interlayer plants in montane forest ecosystems, which play a key role in water balance and nutrient cycling of these ecosystems. This paper systematically studied the species composition and floristic characteristics of epiphytic vascular plants in the Ailao Mountains of Yunnan Province through field investigation, herbarium examination, and related literature review. Results showed that there were 23 families, 83 genera, and 218 species of vascular epiphytes in total. Epiphytic ferns were the most abundant taxa (34 genera and 93 species), with Polypodiaceae (17 genera and 62 species) accounting for 66.67% of these ferns. There were 13 species of Lepisorus and 10 species of Pyrrosia. Most ferns were epiphyte-lithophyte life forms. Orchidaceae (26 genera and 65 species) was the second most abundant taxa and included 12 species of Dendrobium and eight species of Bulbophyllum. Analysis of floristic characteristics at the genus level revealed that epiphytic flora in the Ailao Mountains showed obvious tropic features and was mainly of tropical Asian distribution. As epiphytes are sensitive to environmental change and highly vulnerable to injury, recovery can be difficult once they are damaged. Therefore, more attention should be paid to protect this special and important plant group.