Despite being an important water resource supply area for central and northern parts of China, the Yangtze River Basin (YRB) faces increasing inhomogeneity in water resource allocation and instability in water supply capacity. Recognizing that evapotranspiration (ET) is an essential component that directly affects the basin"s water supply capacity, gaining a quantitative understanding of the physical mechanisms behind ET and its components—soil evaporation (E), transpiration (T), and vegetation interception evaporation (Ei)—offers theoretical and technological insights for the scientific management of water resources in the YRB. Thus, this study conducted a comprehensive investigation of the spatio-temporal variations in ET and its components from 2001 to 2020, utilizing simulations from the BEPS ecological-remote sensing coupled model. Subsequently, a combined approach involving multiple sensitivity numerical experiments was applied to discern the contributions of climate, vegetation leaf area index (LAI), and changes in vegetation types to the variations in ET and its components. Finally, attribution analyses were performed, and the findings indicated that: 1) Except for the annual E with a slight decrease, the annual ET, T, and Ei across the YRB significantly increased by 1.95 mm/a, 1.12 mm/a, and 0.96 mm/a, respectively. Spatially, the significant increases of these three variables were detected across more than 35% of areas. By contrast, the annual E decreased for the whole basin and more than one-half of the YRB. 2) Comparisons between the trends for E, T, and Ei suggested that the T changes for this study region and its 64% areas largely contributed to the ET changes, while the E and Ei changes controlled the ET changes in other areas, corresponding to area percentages of 10% and 24%, respectively. 3) On the regional mean level, the increases in precipitation, air temperature, and LAI positively contributed to the changes in ET and its components (excluding Ei), while the declined relative humidity and incoming solar radiation had negative contributions. As for impacts of the changes in vegetation types, ET and T (E and Ei) responded to increase (decrease). Comparisons between the contributions of these influential variables indicated the increases in ET, T, and Ei and the reductions of E could be attributed to increased LAI. 4) Despite spatial differences in the dominant factors affecting the changes in ET and its components, LAI consistently emerged as the dominant factor across the largest areas, with area percentages of 49%, 46%, 48%, and 73% for the changes in ET, E, T, and Ei, respectively. Over most of the remaining regions, the dominant factors were precipitation and changes in vegetation types for the changes in ET, precipitation, relative humidity, and changes in vegetation types for the changes in E, air temperature and changes in vegetation types for the changes in T, but precipitation for the changes in Ei. Moreover, the area percentages of these dominant factors were all higher than 10%.