Abstract: Nests, eggs and nest site choice of the blackthroated tit Aegithalos concinnus in Zixi Mountain Nature Reserve, Yunnan Province were surveyed from 2009 to 2010 in the spring breeding season and all the relevant features were recorded. Among the 34 nests totally found, 24 were nested in the brushes of Berberis kunmingensis tree species, 8 were nested in Cryptomeria fortunei tree branches. The Principal Compositional Analysis (PCA) on elevation, gradient and other 13 factors related to nesting locality of the blackthroated tit indicated that the principal factors affecting the nest site choice of the bird were ordered as the hiding factor ＞ relief ＞ safety ＞ food ＞ nest tree species. The study also showed that 76.0% of the nests were open to the eastern direction.