This article concerns the process of population concentration in large urban centres in China. The authors conclude that this process is reflected in the increase in the number of cities of a million or more, and the increase in their share of China’s total population, as well as in the country’s total urban population; the process is here termed ‘macropolization’. We analyse and assess the process of macropolization and examine changes in the size structures of these cities (one million or more), and the accompanying transformation in the spatial differentiation of urban population concentrations in China. In addition, the effect that macropolization has on the level of urbanization of individual provinces is shown, as is its significance in the overall share of urban population. The macropolization process from 1950 to 2015 has been assessed. The data was collected from Chinese statistical offices, United Nations reports and the available literature on the subject.