**1. Introduction**

Environmental change is having a huge impact on human society, how to optimize, adjust and reconstruct the interaction between human and natural systems, and how to provide urban residents with a high-quality living environment [1], has become the critical issues faced by human society. At present, it has exceeded that China's population is more than 1.5 billion, and in the future, economic and demographic factors will continue to gather in the medium and long term. Meanwhile, a series of issues such as food security, water resource security, ecological load, and air pollution will be highlighted. From the perspective of the relationship between spatial carrying capacity and sustainability in China, cities, basins and regions are not adapted to resource and environmental carrying capacity. The economically dense megacities such as the Beijing-Tianjin-Hebei Region, Yangtze River Delta, and Guangdong-Hong Kong-Macao Greater Bay Area are closed to or exceed their carrying capacity. It is necessary to coordinate and improve the comprehensive carrying capacity of upper and lower reaches about the river basins [2], due to the Yangtze River, Yellow River, Pearl River, and other river basins connect ecologically fragile highly dense economic areas to many provinces and cities in in China.

This chapter focuses on the relationship between the carrying capacity of different types of space and sustainability, taking the spatial carrying capacity of Chinese cities, river basins and regions under the influence of changes in resource and environmental elements as the research object, and discussing the direction on the improvements on different units adapted to environmental changes.
