Based on the strategic needs of the State Grid Corporation of China in building regional energy Internet, this paper carries out study from the following points: first, analyzing the connotation and characteristics of regional energy Internet; second, building the “three systems”. Based on the strategic needs of the State Grid Corporation of China in building regional energy Internet, this paper carries out study from the following points: first, analyzing the connotation and characteristics of regional energy Internet; second, building the “three systems”. Energy Internet is a concept proposed to harness, control, and manage energy resources effectively, with the help of information and communication technology. It improves a reliability of the system, and provides an increased utilization of energy resources by integrating the smart grid with the. This chapter presents the development of the Energy Internet throughout the history as an evolutionary solution based on modern technological development and needs, with the respect of its architecture, key features, and key concepts, such as energy router, prosumer, and virtual power plant. The. Therefore, a new energy paradigm is known as the “Energy Internet” that combines economics, energy, and technology in an open, equal, and coordinated fashion.