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).

Key words: Yalutsangpu river

摘要： 喜马拉雅东部雅鲁藏布江大峡弯河谷地区植物区系多样性的组成十分丰富，共有种子植物180科，643属，1410种。井有明显的热带向温带过渡的特点，是热带和温带植物区系的两大区系结。它是第三纪以后才发展起来的年轻区系，归根结蒂是源出于古老的东亚植物区系和印度马来植物区系。

关键词: 雅鲁藏布江, 喜马拉雅, 植物区系, 起源