Abstract: To improve the floodwater resources utilization by the reservoir operation and the researching reservoir flood regulation method considering rainfall and runoff forecast information, an operation chart for reservoir flood control is put forward by using 3-hour flood forecast information on the basis of analyzing flood course and reservoir flood control characteristics. Furthermore, taking Ankang reservoir for example, the optimum computation is carried and the operation chart is studied for the purpose of floodwater resources utilization by combining the improved genetic algorithm with the flood routing simulation. By comparing its application with the conventional flood control scheme, the result indicates that the former has apparent advantages in flood peak cutting and water storage at the end of flood regulation, which proves the validity and the advantage of the optimized operation chart.