Abstract: Dangqu River, the south source of Yangtze River, is less studied by researchers due to plateau swamp and poor transportation. The basic characteristics of flow and sediment and its impact on water system of river source are little known to the outside world, with few research results of river evolution and transportation characteristics of flow and sediment. In order to obtain fundamental behaviors such as waterways, flow and sediment of Dangqu, as well as typical landform, researchers in Yangtze River Scientific Research Institute organized scientific investigation for Dangqu River again in 2015. The previous scientific investigation was done in 2014. The investigation results can be used as basic data for river evolution and ecosystem at river bank in plateau, and can be referenced for the harnessing, ecological protection and restoration of other rivers.

Key words: source of Yangtze River, Dangqu River, river system in source region, scientific investigation, river sediment, characteristics of water and sediment