The present study investigates the difference between the interdecadal variability of spring and summer sensible heat flux over Northwest China by using station observational data for the period 1960-2000. It is found that spring sensible heat flux over Northwest China is larger in the late 1970s through 1990s than in the 1960s through mid-1970s, while summer sensible heat flux is smaller in the late 1980s through 1990s than in the 1970s through early 1980s. Both the spring and summer land-air temperature difference over Northwest China displays an obvious interdecadal increase in the late 1970s. Both the spring and summer surface wind speed experiences an obvious interdecadal weakening in the late 1970s. The surface wind speed change plays a more important role for interdecadal variations in sensible heat flux in summer, whereas the land-air temperature difference change is more important for those in spring. This difference is related to seasonal changes in the mean land-air temperature difference and surface wind speed. Further analysis indicates that the increase in spring land surface temperature in Northwest China is related to the increase in surface net radiation.