Population Density Distribution of Main Metropolitan Area in China——Case from Beijing City

During recent years,with the development of central urban district of metropolitan areas in China,their spatial structure have shown some new characteristics.This paper studies the single centric and polycentric models with the help of Arcgis spatial analyzing tools.The study get results as follow:First,the population density curve of Beijing's central urban district is still following Clark's model;Second,this curve is getting more flat and the population density contour is circling the city center;Third,there is no significant sign of polycentric pattern now as the city develops,and the residential centers and industry centers locate next one to each other.