Abstract：In order to solve the problems of intermittent and fluctuating distributed energy，took three major

physical entities in the demand response project，namely system operator，load aggregator and load end user，as the research object，the transactions between supply and demand within the power system composed by them were analyzed，and the objective conditions of the benefits of the whole system load user were considered. The factors affecting the income of load aggregators，system operators and users at the load end were proposed to combined，and an optimal bidding model with multiple types of physical entities under the market environment with the income of load aggregators as the optimization objective was constructed. In the model，the surplus and shortage of system scheduled electricity were directly connected with the power market. A typical case study shows that the optimal bidding model can effectively improve the benefits of load aggregators，and to some extent increase the benefits of load users，and indirectly improve the stability of power system.

      Key words：demand response（DR）；bidding model；load aggregator；optimization strategy