Abstract: Unveiling the trade-off relationship between ecosystem services (ESs) and basic public services (BPSs) and the characteristics of the impact of urbanization on them is of great significance for promoting sustainable development. Taking the Chengdu-Chongqing Economic Circle (CCEC) as an example, this paper quantitatively evaluates the spatio-temporal changes of ESs and BPSs from 2011 to 2021 based on the Sustainable Development Goals (SDGs), analyzes the trade-off relationship between the two using the root mean square deviation (RMSD), and reveals the intensity and direction of the impact of urbanization on their trade-off relationship through the Geographically Weighted Regression (GWR) model. The results show that: (1) All ESs have improved to varying degrees, and the spatial distribution of total ESs is unbalanced, presenting a surrounding structure with high values around and low values in the middle; (2) All BPSs have increased, and the high-value areas of total BPSs have always been concentrated in the main urban areas of Chengdu and Chongqing Yuzhong District, presenting a dual-core structure; (3) The trade-off intensity between ESs and BPSs has increased, showing a spatial feature of high values on the periphery and low values in the middle, with obvious high values in the main urban areas of Chengdu and Chongqing Yuzhong District, and the imbalance between BPSs and ESs persists; (4) In terms of the intensity of influence, the improvement of population urbanization has the most significant impact on the ESs-BPSs trade-off. In terms of the direction of influence, the improvement of economic urbanization, population urbanization, and comprehensive urbanization shows a mitigating effect on the ESs-BPSs trade-off, while the improvement of land urbanization shows an aggravating effect. The research results can provide a reference for the government to formulate sustainable development policies.