Climate change and its uncertainty may cause hydrological cycle and hydropower plant inflow to be changed, which destroy the consistency of hydrological data time series and change the constraint relationships among operation objects of the hydropower plants. So the conventional operation rules cannot be applied to the current hydrological data time series. Therefore, the main goals of this study are to develop adaptive operation chart for the hydropower plant to mitigate climate change impacts, and to propose an optimal adaptive operation chart for cascade hydropower system to increase power generation under the climate change environment. A methodology that combines simulation and optimization models is presented to formulate the optimal adaptive operation rules that consider the joint operation of cascade reservoirs. And the performance of the optimal adaptive operation rules is verified by comparing it with the conventional rules when both been applied to a case study of Hanjiang River hydropower plant reservoirs system. With the optimal adaptive operation chart, the cascade power generation assurance rate increased to 87%, the average annual power generation increased by 16.1%, and the power generation in typical wet, normal and dry years increased by 4.4%, 9% and 7.3%, respectively, compared with the conventional operation chart. (C) 2018 Elsevier Ltd. All rights reserved.