Soil moisture, a key variable in land-atmosphere coupling, significantly influences climate warming. Its pronounced spatial heterogeneity drives substantial regional variations in this effect, but the spatial patterns and underlying mechanisms of these variations remain poorly understood. Using CMIP6 datasets, this study investigates regional differences in soil moisture-atmosphere coupling effects on surface air temperature across the Central-East Asian drylands and quantifies the governing mechanisms through Structural Equation Modeling (SEM). Results reveal that soil moisture-atmosphere coupling amplifies the overall warming trend across the study region, particularly under the long-term high-scenario. This is evidenced by a larger positive surface air temperature difference (0.8 degrees C) between the Scenario Model Intercomparison Project (ScenarioMIP, with fully coupled soil moisture) and the Land Surface, Snow and Soil moisture Model Intercomparison Project (LS3MIP, with soil moisture fixed at 1980-2014 climatology). Regionally, the positive mean surface air temperature differences between the two datasets are significantly larger in Central Asia than in East Asia, indicating that the soil moisture-atmosphere coupling accelerates warming in Central Asia but stabilizes it in East Asia, particularly under long-term high-scenario. Under this scenario, ScenarioMIP projects a warming of 6.5 degrees C relative to the historical period in Central Asia, which is 0.6 degrees C higher than the 5.9 degrees C warming shown by LS3MIP. Conversely, in East Asia, the difference in air temperature anomalies (relative to the historical period) between ScenarioMIP and LS3MIP is only 0.1 degrees C. Mechanistically, in Central Asia, reduced soil moisture enhances surface warming by altering the surface energy balance, thereby elevating surface air temperature. In East Asia, increased soil moisture helps stabilize the warming trend through enhanced latent heat flux. This study suggests that sustaining or enhancing soil moisture levels, potentially through vegetation greening, could help mitigate future warming trends.Graphical AbstractThe graphical abstract offers a visually engaging summary of the research, highlighting key findings, datasets and methodologies. This study investigates the impacts of soil moisture-atmosphere coupling on surface air temperature across Central-East Asian drylands, highlighting regional differences between Central and East Asia, based on the datasets for the Scenario Model Intercomparison Project (ScenarioMIP) experiment (fully coupled soil moisture) and the Land Surface, Snow and Soil moisture Model Intercomparison Project (LS3MIP) experiment (soil moisture fixed at 1980-2014 climatology) from CMIP6 datasets. Furthermore, the Structural Equation Modeling (SEM) is employed to identify the dominant pathways through which soil moisture modulates surface air temperature. The results reveal a significant warming trend across the study region, especially under the high-scenario (1.03 degrees C (10a)-1). The soil moisture-atmosphere coupling amplifies overall warming with positive surface air temperatures differences between ScenarioMIP and LS3MIP, especially under high-scenario. Spatially, Central Asia exhibits stronger warming than East Asia due to the reduction in soil moisture which exacerbates the warming trend through modulating surface energy balance. Under the long-term high-scenario, a - 0.7 mm soil moisture decrease (relative to the historical period) corresponds to a 6.5 degrees C temperature rise for ScenarioMIP, which is 0. 6 degrees C higher than LS3MIP. Conversely, in East Asia, increased soil moisture stabilizes the warming. The graphical abstract effectively conveys research findings through well-designed visual elements including maps, flowcharts, and line graphs. Its logical structure, professional layout, and high-resolution graphics enhance comprehension and the overall impact of the research.