Abstract: Abstract：with operation of reservoirs in the upper Yangtze River with the Three Gorges Reservoir as the core on the period of 2003-2017, the temporal and spatial distribution of sediment in upper Yangtze River has been changed Macroscopically, Jinsha River is no longer the largest sediment supply area for the TGR. The water and sediment transport in the upper Yangtze River is concentrated in the flood season from May to October, the peak of water and sediment between 1956 and 2002 is basically synchronized, but it has changed in the period of 2003-2017, and the flow characteristic curve changed from clockwise to counterclockwise. Though sedimentation in the TGR has been reduced sharply from 2014 to 2017, sediment siltation rate is still high (85.2%). Sedimentation of sediment d < 0.031 mm which can easily flocculated takes up the highest proportion in the backwater area of the TGR（63.5%，2009-2013）, In addition, a large number of sediment flocs observed in the typical river reaches suggest that there is a high probability of fine-grained sediment flocculation in the TGR. Unbalanced water and sediment transport also caused sediment erosion in the reach of Zhutuo-Qingxichang.