Abstract: The coupling population-weighted air pollution exposure risk （PPM_2.5） evaluation system was built, and the spatio-temporal evolution and spatio-temporal clustering of PM_2.5 and its population exposure risk in China was studied based on exploratory spatiotemporal analysis. The results showed that based on the time-space evolution analysis, it was found that there was a spatial mismatch between the coupling population-weighted air pollution exposure risk （PPM_2.5） pattern and the distribution of PM_2.5 concentration.The risk level of PPM_2.5 decreased with the gradient from the center to the periphery, but the overall pattern of high in the east and low in the west remained unchanged during the study period. The spatial and temporal evolution of its equilibrium showed an enhancement of the overall imbalance and the local equilibrium was more likely. Based on the K-means clustering analysis of spatio-temporal scanning statistics, four types of exposure risk were defined： stable low risk, continuous growth risk, continuous high risk and low-high risk gradual change. The distribution of each type was significantly different with different demographic and economic characteristics. The development of differentiated air pollution warning and prevention strategies based on the spatial and temporal clustering zones of different PM_2.5 population exposure risk could help improve urban resilience and provide a theoretical and practical basis for the implementation of the development strategy of “Healthy China”.

Key words: PM_2.5, coupled population-weighted, exposure risk, spatio-temporal trend, spatio-temporal clustering, risk prevention