Abstract: Based on the CHEN-WENG sensible heat coefficient scheme and observational data from 38 meteorological stations in Xizang from 1981 to 2023, the spatiotemporal variation characteristics of Sensible Heat Flux (SH) and its influencing factors over the past 43 years were analyzed using linear equation, R/S analysis and stepwise regression method. The results show that: (1) Spatially, the average SH in Xizang exhibited a meridional pattern in spring, summer, and annually, but a zonal pattern in autumn and winter. Over the past 43 years, SH of most stations showed an increasing trend in spring, autumn and winter, whereas it tended to weaken in summer. (2) Temporally, the monthly average SH in Xizang showed a single peak type with the largest in May and the smallest in December. The seasonal variation was highest in spring, followed by summer, autumn, and lowest in winter. Annual SH showed a V-shaped change over the past 43 years, which decreased significantly at a rate of −3.33 W·m⁻²·(10a)⁻¹ from 1981 to 1996, and increased at a rate of 1.70 W·m⁻²·(10a)⁻¹ significantly from 1997 to 2023, showing a weak increasing trend at a rate of 0.43 W·m⁻²·(10a)⁻¹ in general. SH decreased in summer but increased in the other three seasons, especially in winter. The average SH in summer was strongest in the 1980s and weakest in the 2000s, while SH in the other three seasons and annually was weakest in the 1990s and strongest in the 2010s. In the future, the weakening trend of SH in summer in Xizang will continue, while SH in other three seasons and annual will continue to increase. (3) Over the past 43 years, the dominant meteorological factor affecting annual and seasonal SH in izang was the ground-air temperature difference, with contribution rates ranging from 68.6% to 89.9%, with smallest in spring and largest in winter. Before and after the turning point, the ground-air temperature difference also played a leading role in the annual and seasonal SH changes in Xizang, with its contribution increasing significantly after the turning point. The decrease in the ground-air temperature difference, caused by air temperature warming faster than ground temperature, was the main cause of weakened SH in summer. In contrast, the increase in the difference, caused by a lower air warming rate, was the dominant factor for enhanced SH in spring, autumn, winter, and annually.