Abstract:Endophytic bacteria play an important role in the life history of orchids,which influence the formation of mycorrhiza and stability of plant-fungi interaction. Endophytic bacteria could promote growth and development of orchids by secreting phytohormone, conducting photosynthesis, fixing nitrogen or promoting the cycle of mineral nutrition, producing siderophore and secreting other active substances. The research methods of the diversity of endophytic bacteria associated with orchids, and their growth-promoting mechanism were reviewed. Based on the close relationship between orchids and symbiotic microbe, the studies on interactions between endophytic bacteria and mycorrhizal fungi will be an important direction to reveal the mechanism of orchid-endophytic bacteria interaction.