The change in species diversity and composition of vascular epiphytes along disturbancerngradient was studied in Yayu forest of southwest Ethiopia. Systematic sampling method wasrnemployed in data collection with a line transect was laid out along disturbance gradient of thernforest. Based on their increasing level of disturbance, the forest was divided into threernmanagement zones: natural forest (core zone), semi-forest coffee production system (bufferrnzone) and agricultural matrices (transition zone) respectively. A total of thirty-six species ofrnvascular epiphytes were recorded from thirty-five host (phorophyte) species in the study area.rnEach forest zone harbored considerable number of epiphyte species, 31 species in core zone,rn32 species in buffer zone and 24 species in transition zone. This indicates the existence ofrnchanges of species diversity along disturbance gradient of the forest due to anthropogenicrndisturbance. The species diversity of vascular epiphytes is also greatly influenced by thernphorophyte biophysical factors, such as vertical gradient on individual host plants, host size,rnbark texture and elevation. Thus, vertical distribution of vascular epiphytes indicated thatrnspecies diversity increases from phorophyte base to the canopy. The larger and older trees ofrnthe same offer more surface than small trees and also have been available for a longer timernthan younger hosts for epiphyte colonization. Rough bark texture of the phorophytes has highrnwater retention capacity and is more convenient for vascular epiphyte species establishmentrnthan smooth ones. The changing forest structure and tree species composition at increasingrnaltitude provide different quantities and qualities of substrate to epiphytes that resulted inrndecreasing number of epiphyte species with increasing elevation. Furthermore, host preferencernof vascular epiphytes was apparently exhibited by few species such as: Angraecopsisrninfundibulum, Polystachya cultriformis, Vittaria volkensii, Chlorophytum comosum andrnColeochloa abyssinica.rnrnKey words: Disturbance Gradient, Diversity, Phorophyte, Species composition, Speciesrnturnover, Vascular Epiphyte, Yayu Forest.