Abstract: Jigongshan Mountain is the western mountain chain in the Dabie Mountain, located at the boundary between Hubei Province and Henan Province, which is the national natural sanctuary and landscape region.Based on thorough and careful statistical analysis of families, genera and species in the present flora and comparison of the retated regions' floristic elements, the results are shown as follows.1. The plant species and composition are very rich. There are 132 families, 544 genera and 1161 species in the area of 100 square kilometre.2. Jigongshan (Dabieshan)is the area where East China, Central China and North China flora are covcrgent, and various floristic elements are compatible.3. This area is the natural boundary of the plant distribution between subtropicus and warm temperate zone. There are 34 genera and 72 species whose distribution are bounded on north by Dabie Mountains.4. Dabie Mountains is the north passageway of plant spread, where floristic elements can spread from Southwest China and Central China to East China, or from East China to West China and Central China. Jigongshan isthe tie of the passageway.