Gaoligong Mountain(hereafter, GLGM) is located at the intersection of Myanmar and China’s Yunnan Province and Xizang Zizhiqu, and spans three globally significant biodiversity hotspots: the Himalayas, Indo-Burma, and the Mountains of Southwest China. Although surveys of mammals in this ecologically important region have a long history, there is no comprehensive systematic checklist and distribution account of the mammals of GLGM. Here, we compiled a mammal species checklist of GLGM based on thorough field investigations and literature reviews. We also examined specimen collections and applied camera trapping surveys to explore the region’s mammal diversity and distribution patterns. We recorded 212 mammal species in nine orders, 33 families, and 119 genera, which accounts for 30.5% of China’s mammal species, and a high proportion of nationally protected(50) and globally threatened (29) species. Mammal species richness showed a symmetrical unimodal curve along the elevation gradient, peaking at intermediate elevations(2 000 to 2 500 m above sea level (asl)), and increasing generally from south to north, slightly higher in the east slope than in the west. Cluster analysis and non-metric multidimensional scaling revealed three distinct elevational assemblages (< 900 m asl., 900–3 500 m asl., and> 3 500 m asl) and significant south-to-north variation, but no substantial differences between the east and west slopes. The GLGM present a unique conservation value due to the high proportions of rare and endangered mammal species, complex faunal composition, high endemism, and being the distribution boundary for many species. This study is an important phased account of mammal diversity in GLGM and makes a prospect for future research.