Due to the lack of competition and unbalanced demand/supply situation in the current power market, deregulating the power sale market has become the core of further reform of the electric power system. Its key task is to balance supply and demand by introducing competition on the demand side, releasing user selection and dynamically integrating demand?side resources.Therefore, demand side management（DSM）has become the key technology for orderly release of power sale market. Based on the gradual deregulation of the power sale market in China’s current electric reform, the resulting multi?buyer?multi?seller market structure is revealed. Secondly, the key technologies and implementation obstacles of DSM are reviewed in detail. Thirdly, it is discussed how to promote and develop the DSM through competitive market mechanism and flexible market environment brought by the opening of the sale side. Fourthly, the successful applications of DSM in the international power market are introduced. Finally,based on the national conditions, the implementation stages and recommendations for the DSM are proposed under the condition of deregulated power sale market.