Abstract: It is now known that there are 1108 species (including varieties) of vascular plants, in the Tiantangzhai Mountainous region, which belong to 565 genera and 152 families. The Dabieshan Mountains first took shape in the Sinian Period. The origin of the flora of the Dabie Mountains is very ancient, and the flora originated principally from the Tertiary ancient tropical flora. There are many ancient families and genera as well as many relic species. There are all told 81 monotypic and oligotypic genera which are genetically ancient or primitive in the Tiantangzhai Mountainous Region The flora of the Dabieshan Mountains comprises a portion of the flora of East China. In this paper, author has drawn a clear line of demarcation between East China and Central China, from Yichang to Xiangfan in Hubei Province; and a dividing line between East China and North China, through the Tongbaishan Mountains from the Southern foot of the Funiushan Mountains to Huai river.

Key words: The Dabie Mountains, Flora, Boundary