Abstract: In order to fully exploit the flood control benefit of 1 billion cubic meters of Qingjiang cascade reservoirs，this study constructed a joint flood control operation model of cascade reservoirs in the upper reaches of Changjiang River and Qingjiang cascade reservoirs.We quantitatively analyzed the flood control effect and storage capacity utilization of Qingjiang cascade reservoirs under cooperation with the Three Gorges Reservoir to Jingjiang Reach.The necessity of joint flood control operation to Chenglingji Area by Three Gorges Reservoir with the cooperation of Qingjiang cascade reservoirs was discussed.Based on the comparative analysis of joint flood control effect with different operation schemes，the graded storage scheme to Chenglingji Area by combining Qingjiang cascade reservoirs with Three Gorges Reservoir was proposed.The proposed graded storage scheme is that: when the inflow is less than 4 000 m3/s，the stored flow of each Qingjiang cascade reservoir is 2 500 m3/s；when the inflow is not less than 4 000 m3/s，the stored flow of each Qingjiang cascade reservoir is 3 000 m3/s.And during the water storage process，the impounding timing is synchronized with the Three Gorges Reservoir，and the power generation factor is also taken into account.The research quantified the flood control function of Qingjiang cascade reservoirs and strongly supported the formulation of joint flood control operation scheme of Changjiang River reservoir group.