Whether China can escape the middle-income trap is mainly an issue of raising income in its less-developed regions. This goal can only be achieved by strengthening the role of large cities and their metropolitan areas and promoting regional agglomeration，interregional specialization and the efficiency of labor force allocation. For the whole country，the interregional mobility of production factors will improve the allocative efficiency of resources so that the economy can follow a development path of “balance through agglomeration” to escape the middle-income trap.