Abstract: The Yangtze River Economic Belt is an important contributor to China′s carbon sink. Exploring the spatiotemporal evolution and driving mechanism of carbon sinks is beneficial for promoting carbon reduction and increasing carbon sinks and regional low-carbon development. This paper analyses the spatiotemporal evolution characteristics and driving factors of carbon sinks in the Yangtze River Economic Belt based on land use data, socio-economic data and other data from 2000 to 2020 by using standard deviation ellipses, center of gravity migration models and geodetector. The results show that: (1) Temporally, both the total amount and intensity of carbon sinks in the Yangtze River Economic Belt show a fluctuating and increasing trend from 2000 to 2020, but the intensity of carbon sinks in the middle and lower reaches fluctuates more frequently in time sequence, woodland had the largest carbon sink, and the average annual carbon sequestration is about 6817.66×10⁴ t. (2) Spatially, the intensity of carbon sinks at the provincial scale shows a distribution pattern of ‘high in the south and low in the north, high in the west and low in the east’. The distribution of total carbon sinks and woodland carbon sinks has a strong spatial consistency, concentrating in the middle and upper reaches and showing the characteristics of expansion followed by contraction and migration to the west. The carbon sinks of water are mainly in the middle and lower reaches, showing a westward expansion trend. The carbon sinks of grassland and unused land are mainly distributed in the western plateau of Sichuan Province and have contracted. (3) In terms of the migration of the center of gravity, woodland carbon sinks follow a similar trajectory to the total carbon sinks, moving northeast and then west, with cumulative migrations of 18.81 and 17.76 km, respectively; grassland carbon sinks move 21.76 km to the north and unused land carbon sinks move 32.38 km to the west; in contrast, watershed carbon sinks move the longest distance, with a cumulative move of about 73.46 km to the west. (4) In terms of the influencing factors, the size of carbon sinks in the Yangtze River Economic Belt is influenced by a combination of both natural and socio-economic factors, natural factors have the greatest influence, and national policies and land use intensity among the socio-economic factors also have a more significant influence; the impact of any two drivers when they interact is greater than that of a single factor. The study shows that the spatial and temporal evolution of carbon sinks and the influencing factors vary significantly in various regions in the Yangtze River Economic Belt. Therefore, it is recommended that each region should seek differentiated low-carbon pathways and optimize the structure of land for carbon sinks, and formulate environmental policies and land use plans to promote regional carbon sink potential and low-carbon development.