Objective/Meaning Deepening the understanding of the population distribution law in the western economic circle of China aimed to provide scientific basis for the development strategy planning and the optimal allocation of public service resources in the Chengdu-Chongqing economic circle.

Methods/Procedures By taking districts and counties as the units, the spatial distribution and evolution trend of population in Chengdu-Chongqing economic circle were investigated. Based on the data of three population censuses and county statistical yearbooks from 2000 to 2020, the characteristics of population distribution evolution in this area and the influencing factors of population distribution were analyzed by using the methods of spatial autocorrelation and geographically weighted regression.

Results/Conclusions The results showed that: (1) The population was mainly concentrated in the central urban areas of Chengdu and Chongqing, presenting the overall form of “double-yolked egg”; (2) The trend of population aggregation in Chengdu and Chongqing was continuously strengthening, and it has gradually expanded to the surrounding counties; (3) The population gravity center was generally moving from east to west in a slightly northern direction, but still located in the central part of the Sichuan Basin; (4) The high added value of the tertiary industry had a positive incentive effect on the distribution of population density, while the added value of the secondary industry and the increase in the number of full-time teachers in the general high schools had a negative correlation with the distribution of population density. The number of beds in the hospitals and health centers, the average elevation of the region, and the average slope gradient had a more complex impact on the distribution of population density, with both positive and negative effects.