City-Size Distribution and Industry Agglomeration: An Empirical Analysis Based on the County - level in Beijing-Tianjin-Hebei Region

The urban agglomeration of the Beijing-Tianjin-Hebei region is the core development engine of the Bohai Economic Circle area. However, over the years, because of regional and local competition, the level of integration is low in the city circle, the gap is large in the region, the flow and distribution of population is extremely uneven, which is described as "the coexistence of advanced European cities and backward rural Africa" by educational circles. In the 2014, the cooperative development among Beijing-Tianjin-Hebei has become a major national strategy, highlighting the urgent realistic needs of "To build a new capital economic circle for facing the future and promote the innovation of regional development system". The country has established national new district in Xiongan in 2017, which is a millennium plan and national affairs. Besides, as the key content in research of the coordinated development among the three cities, the research on the optimization of population distribution and the realization of system is not only has the urgent need of reality, but also has important reference value to explore the theory and practice mode of China's regional integration in the future.