Abstract <p>With the acceleration of urbanization and rapid economic development in the Sichuan-Chongqing region, air pollution has become an increasingly evident problem. Based on hourly air quality index (AQI) concentration data from 2016 to 2020, this study used statistical and interpolation analysis methods to explore the spatiotemporal variation characteristics of AQI in the Sichuan-Chongqing region at annual, seasonal, and monthly time scales. Moran’s I Index and hot spot analysis characterized the spatial agglomeration of AQI and air pollutants. The main results are as follows: (1) From 2016 to 2020, the annual average AQI value in the Sichuan-Chongqing region decreased, and the air quality improved significantly. The characteristics of seasonal and monthly variation of air quality are obvious. The spatial distribution shows the characteristics of “better in west and north, worse in east and south”, which highly coincides with the difference in terrain characteristics in the region (2) In 2018, AQI, PM_2.5, PM_10, SO₂, NO₂, O₃, and CO showed clear spatial dependence, and each air pollutant showed regional differences in the distribution of hot spots. (3) The air quality in Sichuan-Chongqing region is affected by both natural factors and social and economic factors, but the influence of natural factors is more significant. The research results provide a scientific and theoretical basis for air pollution governance and ecological civilization construction in the Sichuan-Chongqing region.</p>