Abstract:[Objective] The spatial variation of soil moisture under different slope conditions in fixed sand dunes in semi-arid area was studied in order to provide decision-making basis for the optimal management of soil moisture in fixed sand dunes. [Methods] In the Mu Us sand land controlled and afforestation base of Shenmu ecological association of Shanxi Province in the southeastern edge of Mu Us sand land, the 12-year-old artificial Amygdalus pedunculate woodland in fixed dunes was taken as the research object. Soil moisture observation plots were established and CNC503DR neutron meter was used to measure soil moisture in 0—300 cm soil layer from July to October in 2018. The spatial and temporal variation characteristics of soil moisture during the growing season of Amygdalus pedunculate were analyzed under different slope conditions. [Results] ① Soil moisture content of the 0—300 cm soil profile at the top and upper slope increased firstly and then decreased with the increase of soil depths, and then tended to be stable. However, the soil moisture variation of the middle (upper and lower) of the slope and the bottom of the slope showed a S-shape pattern. Soil water content and storage showed as:slope bottom > middle slope (upper) > the upper slope ≥ slope top > middle slope (lower). ② The soil moisture content at the lower slope showed strong variability, while the other four slope conditions showed moderate variation. ③ Thevariation of evapotranspiration (ET) was as follows: bottom of slope > top of slope > middle of slope (lower) > upper of slope > middle of slope (upper). The variation of ET on slope bottom was medium and the coefficient of variation was the smallest. [Conclusion] Different slope conditions had important effects on fixed dune soil moisture and ET. Soil moisture content and ET at the bottom of slope was the highest and showed a strong instability.