Abstract: To explore the relationship between soil moisture and its influencing factors in the root zone of different mixed shrubs in the middle reaches of Heihe River, and to provide reference for the rational allocation of plants in the wind and sand fixation project in the future.In the desert-oasis transition zone of the middle reaches of the Heihe River, the mixed shrub Haloxylon×Sphaerophorus, the mixed shrub Calligonum×haloxylon, and the mixed shrub Calligonum×Sphaerophorus were selected as the research objects, and the soil moisture content and main soil physicochemical indexes were measured and analyzed in the 0～120 cm soil layer of the root zone of the three mixed shrubs.The results showed as follows: The soil moisture content in the shrub root zone first increased and then decreased with the increase of soil depth from May to August, and gradually increased with the increase of soil depth from September to October.The soil moisture content of interlunar Haloxylon×Sphaerophorus root area was higher than that of the other two mixed shrubs.Soil moisture content in root zone of three different types of mixed shrubs showed significant differences between species, and monthly soil moisture content of mixed shrubs of the same type also showed significant differences.Soil water content in the root zone of the three mixed shrubs was negatively correlated with soil bulk density, but positively correlated with organic matter content, capillary water capacity and total porosity.The organic matter content, capillary water capacity and total porosity in the root area of Haloxylon×Sphaerophorus were superior to those of the other two mixed shrubs.Among the three mixed shrubs, Haloxylon×Sphaerophorus had the most outstanding improvement on soil physical and chemical properties, and could better preserve soil water.The future research area should be the mixed planting of Haloxylon and Sphaerophorus.