In arid and semiarid regions, soil moisture can effectively promote tree transpiration. Soil moisture replenishment, as an input underlying soil moisture dynamic, inevitably affects tree transpiration. Although many previous studies have investigated soil moisture effects on tree transpiration, few have addressed soil moisture replenishment effects, especially lateral replenishment at different slope positions along hillslopes. In this study, we tested how soil moisture replenishment and lateral replenishment at different slope positions affect stand transpiration. Meteorological conditions, sap flow, and soil moisture were monitored during the growing season (May to October) from 2021 to 2023 on a larch hillslope in the Liupan Mountains, Northwest China. Our results showed that the stand transpiration differed among slope positions in years with different precipitation pattern. The daily stand transpiration (mmday(-1)) was ordered upslope (0.66) > midslope (0.57) > downslope (0.41) in normal years and midslope (0.53) > upslope (0.44) > downslope (0.35) in summer drought years. However, the difference in stand transpiration was reduced among slope positions in relatively wet years. The daily stand transpiration increased with increasing soil moisture replenishment levels, suggesting that soil moisture replenishment effectively promoted stand transpiration, which was the most pronounced at the midslope position. Lateral replenishment played an indispensable role in stand transpiration, especially at the midslope position, with a contribution of 11.3 %. These results suggest that lateral replenishment plays an important role in redistributing soil moisture on hillslopes and has an essential effect on tree transpiration and thus could provide guidance for site selection for vegetation restoration in water-scarce areas.