Abstract: We select Gezhouba and Three Gorges cascade reservoirs as the research object and divide study periods into 4 sub-periods in accordance with different operation phases of the reservoirs. Based on daily water discharge and sediment concentration data at Cuntan, Yichang, Hankou and Datong hydrological stations from 1954 to 2008, the change of sediment load and flow-sediment relationship of mid-lower Yangtze River under the operation of the cascade reservoirs is studied. The results reveal that the annual sediment load and sediment concentration at 4 hydrological stations are in a decreasing trend in general; the impact of the operation of cascade reservoirs on sediment load and flow-sediment relationship is related to the storage capacity and the distance from reservoir; the sediment decrease caused by reservoir retaining is related to seasonal distribution changes of runoff but not to the annual runoff volume variation; the annual distribution of monthly sediment load at Datong Station becomes more even due to the seasonal distribution changes of runoff volume and reservoir retaining.