State and causes to China’s city size polarization

In the process of urbanization, city's distribution and resource allocation have crucial influence on the stable development of China's economy. With the theories on urban cost and income, sequence-size distribution and network cities, this article analyses the data of population, economic output, the allocation of resources in our different cities, and discusses the reason of the polarization of China's city size in three aspects: market selection, political system, natural and historical factors. Finally, this article concludes that education and medical resources should be guided to small and medium-sized cities, and different scale cities should be developed coordinately.