Abstract: In allusion to different operation conditions of distribution network, considering operation strategies of microgrid clusters and the influence of collaborative operation of sub-microgrids on distribution network, a two-stage optimization model for site selection of energy storage allocation and their capacity determining for distribution network was proposed. In the first-stage, the lowest operating cost of the distribution system was taken as the objective on the time scale of daily operation, and the position and the number of the energy storage equipment as well as the charge-discharge strategies were solved by GAMS software; for the capacity optimization model in second-stage, the lowest yearly operating cost consisted of the investment, operation and maintenance of the energy storage equipment in distribution network was taken as the objective on the time scale of one year, and the particle swarm optimization algorithm, in which the nested energy storage life calculation was utilized, was used to be solved in MATLAB software. Results of calculating example show that under different operational scenarios, the optimal configuration method of energy storage equipments in distribution network, in which the economic operation of microgrid clusters and distribution system are taken into account, can effectively reduce the operational cost of distribution network and the investment and maintenance cost of energy storage, thus the economy of distribution network can be improved.