As one of the world's biodiversity hotspots, Hainan Island is widely recognized as a distinct biogeographical unit in zoogeography of China. The aim of this study is to analyze whether there are groups of mammalian assemblage that share similar geographical distributions (chorotypes) in Hainan Island and to reveal the faunal similarity between the island and its adjacent areas. Environmental correlations are also carried out to interpret the formation of these chorotypes. I employed cluster analysis with statistical test to detect chorotypes and then used logistic regression analysis to identify favourable environmental factors that potentially explained the distribution of each chorotype. Common species of Hainan Island shared by different Asian countries were gathered to infer the faunal relationship between Hainan Island and adjacent areas. Results showed that there were fourteen mammalian chorological patterns in Hainan Island; Hainan was close to Southern and Southeastern Asian countries based on their faunal similarity. Precipitation and temperature were the main factors driving the spatial patterns of mammals in Hainan.