Abstract: The present resources of Rhynchostylis gigantea in Hainan were investigated by combined route research method, field investigation and site visits in this paper. After finishing the surveys of more than two-thirds of the towns in Hainan (more than 130 towns) , 22 populations of R. gigantea have been found, they distributed mainly in Baisha, Qiongzhong, Wuzhishan, Danzhou, Ledong, Changjiang, Dongfang, Baoting, Lingshui. It likes growing on tall trees that grow in well-ventilated, moist and well-lighted valley at elevations between 40 and 700 meters. The phorophytes species include 17 species belonging to 15 genera and 13 families. In the communities of R. gigantea, the dominant species mainly include Liquidambar formosana, Bischofia polycarpa, Bombax ceiba Linnaeus, Mangifera indica, Vitex quinata. This paper not only evaluated the endangerment category and analyzed the main threats of R. gigantea in Hainan, but also put forward feasible measures for protection.