Energy-saving power generation dispatching is a multi-objective optimization problem with constraints.The centralized dispatching scheme requires heavy computational burden thus is hard to realize in real time.Further,it is difficult to obtain the coal consumption characteristics of units on-line and it has severe effects on system stability in case of faults.To overcome these problems,a hierarchical optimization scheme was proposed.At the power grid level,load demands for power plants are computed incorporating system stability and economic issues;at the power plant level,the load demand is dispatched to each unit according to the real coal consumption characteristics.Analysis shows that the hierarchical optimization scheme is superior to the centralized one,and an effective scheme for compromising both the benefits of the power grids and power plants.