Under the communist regime, the Chinese government has developed policies both to limit the growth of large cities and to promote spatial equity in population distribution. The literature provides only very general and inconclusive results regarding the impact of these policies. This paper aims at evaluating the effectiveness of China's urban policies by investigating the temporal and spatial dynamics of the size distribution of China's cities during the period 1922–82. The research framework — which is based on a function relating population size to rank —is used to test for trends of deconcentration (where smaller cities grow faster than larger cities) and spatial decentralization (with a more even spatial distribution) of population over the study period. More formally, the ‘expansion methodology’ is used to investigate the dynamics of the rank-size function in both temporal and spatial dimensions. The findings show that from 1953 to 1970 there was significant population deconcentration, which appeared to be reversed subsequently. However, policies of spatial decentralization were not found to be successful. Among the reasons suggested for the apparent failure are political upheavals and shifts in policies, the inertia within the urban system, the harsh physical environment in the interior, and current trends in economic policies that focus on the coastal areas. In spite of recent criticisms of studies on city-size distributions (which this paper also discusses), the research framework proposed and utilized here is able to portray the dynamics of a national urban system, and the framework can be used to evaluate national urban policies.