[Objective] The dynamic characteristics of soil moisture in sandy arid lands were analysed to provide scientific support for desertification control. [Methods] Sandy land (mobile dunes, semi-fixed dunes, fixed dunes and shelter forest) in east of the Yellow River in Ningxia Hui Autonomous Region was selected as the research object. According to data from the positioning observation and automatic observation systems, the soil moisture distribution characteristics of sandy soils (0—150 cm depth) were analysed. [Results] ① Changes in soil moisture content in the different plots showed a consistent pattern with time. Changes in soil moisture content could be divided into three periods: the soil moisture accumulation period from April to May, the soil moisture consumption period from June to August, and the soil moisture stable period from September to November. ② The soil moisture content in the 0—10 cm topsoil layer was significantly different in the three periods, whereas the soil mositure content in the 40—150 cm soil layer did not differ significantly. ③ The topsoil (0—20 cm) was the active layer of soil moisture, 20—40 cm was the subactive layer, and 40—150 cm was the stable layer of soil moisture. ④ The soil moisture content between the different plots was as follows: moving dune > shelter forest (Salix matsudana, Populus bolleana, and Pinus sylvestris forest) > fixed dune (Hedysarum scoparium forest) > fixed dune (Calligonum mongolicum and Caragana korshinskii forest) > semi-fixed dune (C. mongolicum and C. korshinskii forest). ⑤ The soil moisture content in different terrain parts decreased from the slope bottom > slope middle > hill top. [Conclusion] The vertical distribution and stratification characteristics of soil moisture in the sandy arid lands in east of the Yellow River in Ningxia are clear. Changes in soil moisture content are not only affected by rainfall, vegetation type, and vegetation distribution patterns, but also by the microgeomorphology of the sand dunes.