Abstract: Based on the spatial differences in urban ecosystem carrying capacity, and by using geographic information system (GIS) spatial analysis technology and system dynamics (SD) model, this paper ascertained the moderate population size in urban area and its subareas, and presented an alternative method for quantitatively allocate the population. This method was applied in Changzhou, a city with more than three million populations in East China. A SD model consisted of population, economy, land and environment modules for the city was established and scenario analysis was made. The results showed that under the requirements of satisfying both economic development and environmental protection, the total population in the city in 2050 would reach nearly 4 million, and according to the differences in the urban ecosystem carrying capacity, a spatial allocation pattern of 2.4 million populations in main city and 150000-400000 populations in each of 5 new towns was proposed. This study could provide scientific support for the spatial allocation of population and economy in country land development and management.

Key words: carrying capacity, spatial allocation of population, system dynamics, Changzhou