Abstract: Dabie Mountain is situated in the area which bounderes with three provinces (Anhui, Hubei, Henan). The northern part of Mt. Dabie in Anhui is the main part of whole Mt. Dabie, and is one of the areas where natural forest vegetations are well preserved. By means of the contrastive analyses of the floristic elements and the shared plant species between Mt N. Dabie in Anhui and the adjacent floristic regions, the results show that:(1) The northern part of Mt. Dabie in Anhui is the closest to East China in flora, next to Central China, thirdly to Japan, fourthly to North China, fifthly to South China, sixthly to Southwest China and seventhly to Northeast China; but scarcely with Northwest China and Qinghai-Xizang plateau; (2) The floristic relation of the northern part of Mt. Dabie in Anhui with Japan is closer than that with Southwest China; (3) According to the floristic relation between the northern part of Mt. Dabiein Anhui and adjacent mountains from much closer to little closer, the sequence is Mt. Tiemu in Zhejiang Province, Mt. Lushan in Jiangxi Province, Mt. Shennongjia in Hubei Province, Mt. Wuyi in Fujian Province, and Mt. Zhongtiao in Shanxi Province; (4) The author believes that the flora of the northern part of Mt. Dabie in Anhui should be an integrated part of the Flora of East China; (5) On the regionalization of Chinese flora, the author's view is that the demarcation line between East China region and Central China region in Huhie Province should be from Xiangfan to Yichang, and the demarcation line between East China region and North China region in Anhui Province should be from Huoqiu to Chuxian.