With the impoundment operation of the Three Gorges Project and the successive application of Xiangjiaba and Xiluodu reservoirs in its upstream,the sediment inflow in the downstream reaches of the reservoir is greatly reduced,the scouring of clear water is serious,and the evolution characteristics of the river channel are significantly changed.The situation has an impact on flood control,navigation and the utilization of the shoreline.Based on the analysis of prototype data,we study the characteristics of water and sediment movement and riverbed evolution in Xiong-Cheng reach(Xiongjiazhou to Chenglingji)of Jingjiang River under the condition of scouring sand.On this basis,we predict the scouring and silting volume,scouring and silting distribution and river regime change of Xiong-Cheng reach after 30 years of operation of the Three Gorges Project by combining with solid model tests.The results show that the Xiong-Cheng reach will continue to scour in the future,and the deep trough will continue to deepen and widen,which is not conducive to the stability of the channel.