This chapter analyzes the formation of an interregional network under the socialist system, focusing on the case of the Shanghai power industry from the immediate postwar period to the planned economy period. Since before the Second Sino-Japanese War, the Shanghai power industry possessed a rich electricity generation capacity fueled by foreign companies, and was structurally independent from neighboring regions. However, after the establishment of the PRC and the outbreak of the Korean War, the industry was reorganized under the control of the Chinese government and was connected to an interregional power network, the East China Power Grid. As a result, Shanghai became an importer of electricity from other provinces within the grid without itself carrying out large-scale power source development. The upshot of this process is that within a government-led interregional network like what had been established in the PRC, the characteristics of the Shanghai power industry that had developed during the Republican period had no choice but to undergo a dramatic transformation.