Abstract: Smart grid is the final aim of power system development,in which the energy storage technology is a very important component.In this paper,the existing energy storage technologies were plotted out to the three different main application occasions with utility side,user side and renewable energy generation.The application planning and benefit assessment methods were studied and summarized.The difference between objective functions,constraints and solving methods of the relative research models were analyzed.The advantages and weaknesses of the current researches were pointed out.Finally,this paper illustrated the further considerations needed in the energy storage planning and the aspects should be concerned in the application popularization process.