The Definition and Development of Metropolitan Areas in China Based on the Data from the 6~(th) National Census

The cities in China are the administrative regions of different scales, and they are actually a kind of the city-region. So, the population size of a city in China can not represent the city's real urban size. Based the concept of metropolitan area and the urban-rural definition from the 6th National Census, and adopted the related indices of population density and urbanization rate at the same time, the article firstly identified 128 metropolitan areas of China in 2010. Secondly, the article studied the characteristics and change of population size and spatial distribution of metropolitan areas of China. Structurally, the scale of population size in urban China obeys the rank-size rule, while the index of q rose from 0.787 to 0.891 in past 10 years which indicated the concentration of metropolitan system in China; nevertheless, the model of mega metropolitan areas has been seen since 2000, and there remains to be some developing space for those advanced metropolitans. Spatially, most metropolitan areas concentrate in the Eastern China, and three metropolitan interlocking regions have been emerging; the number of metropolitan areas is increasing in Middle China, but the population proportion accounted for the total population of metropolitan areas is lower; the development of metropolitan areas in the Western China lags behind other areas, with a characteristics of polarization. Lastly, the paper put forwards some suggestions.