Abstract:The flora of the big bend gorge (below el. 2500 m) is very rich, which comprises ca. 1410 species of seed plants in 643 genera, 180 families. The noristics of the region has obviously transitional characters between tropical and temperate, and it is a knot of tropical and temperate flora. In the origin, it mainly originated from the Eastern Asia, which developed into Sino-himalayan elements in Hengduan Mts or S.W. China after tertiary, and the tropical Asia (Indo-malayan).