The survey of the Orchid flora at Hon Ba Nature Reserve, where was a part of the famous Annamite Range in Vietnam, had been achieved from March to December 2014. A total of 106 species in 4 life forms were accounted i.e. epiphyte (67 species), terrestrial (20 species), lithophyte (13 species) and mycoheterotrophic (6 species). Among those, there were two newly recorded species to the Annamite Range i.e. Lecanorchis nigricans Honda and Bulbophyllum dasystachys J.J.Verm., P. Thavipoke & J. Phelps. The most diverse genera were Dendrobium, Bulbophyllum, Liparis and Paphiopedilum respectively. The result area revealed that the Annamite Range performed as a “cross road” of 4 floristic regions in Asia, i.e. the Himalayan Range, the Indo-China Mainland and Myanmar, the Sino-Japanese and the Malesian Region.