Abstract: An optimal capacity allocation method for regional integrated energy systems with electric heating energy transactions is presented in this paper to promote and achieve coordination, complementarity and high-efficiency utilization of various forms of energy resources such as electricity, heat, cold energy. The cost of energy exchange between the system and the grid is taken into the total cost. A multi-objective function, considering the economy, environmental benefits, reliability and exchange power fluctuation, is proposed to optimize the capacity of energy supply equipment in the region based on the energy hub. The genetic algorithm is used to solve the model based on time-of-use price and the typical daily operation scenario. Finally, an example of a certain park is given to verify its effectiveness. The results show that the proposed method can effectively reduce the system cost and avoid the limitations caused by the single decision factor in the system planning stage, and provide a reference for the planning and design of the actual system.