<p>Exploring the dynamics of carbon sink capacity (CSC) driven by climate change is essential for understanding the carbon cycle within terrestrial ecosystems. In this study, we examined the spatial and temporal variations in CSC within the Three Gorges Reservoir Area (TGRA) from 2000 to 2020. We utilized net primary productivity (NPP) data from the MOD17A3HGF yearly composite dataset and calculated net ecosystem productivity (NEP) as a proxy for CSC. By employing partial correlation analysis, we explored the effects of climatic factors on CSC and identified the dominant factors influencing CSC in the TGRA. The analysis indicated distinct regional characteristics in CSC within the study area during the period. Notably, a consistently increasing trend in CSC was observed in over 90% of the TGRA. Precipitation emerged as the most significant influencing factor for CSC, positively impacting CSC in the majority of the TGRA (88.93%). Specifically, precipitation and temperature were identified as the primary influencing factors in the head and middle regions of the reservoir, while radiation had the greatest impact in the tail region. Furthermore, an analysis of the Hurst index revealed uncertainties regarding the future development of CSC in 75.33% of the TGRA. Despite the overall increasing trend in CSC and the potential for enhanced regional carbon sequestration, uncertainties regarding future trends in regional CSC persist due to climate change. It is imperative to strengthen the stability of the regional ecosystem to ensure sustainable development in the future. This study concludes that the head and middle regions should optimize water resource management and enhance vegetation adaptation by planting drought-tolerant vegetation species. The tail area should optimize land use and vegetation configuration to reduce the negative impact of radiation on the ecosystem carbon sink.</p>