In the arid areas, the precipitation is less,and the soil moisture is one of the important factors to maintain the growth
of natural vegetation. The spatial
distribution of soil moisture content is quite different from the different regions due to the influences of the different regional landforms, soil properties, depth of groundwater level, etc. In order to analyze the
spatial variability of soil moisture content and its distribution trend in the oases in arid areas, in this paper the spatial variability of soil moisture content in the Sangong River watershed is analyzed based on the measured data of soil moisture content in the watershed by using the spatial analysis method of geography information system (GIS), and the distribution laws of soil moisture content are discussed and estimated. The results show that the spatial variability of soil moisture content accords with the ecological characteristics in the oasis, the ecological effects vary with the change of many factors including the cropping and irrigation systems, distribution and redistribution of water resources, etc., thus, the self-correlation of soil moisture content is reduced. The influence of landforms on the soil moisture content is dominant in the watershed, and the influence of the river channel on the moisture content in deep soil is more obvious than that in topsoil. Analyzing from the temporal variability, the soil moisture content in higher in summer than that in autumn because of the increase of precipitation, inflow and irrigation in summer. The temporal change of soil moisture content in shallow layers 10～30 cm and 30～45 cm in depth is obvious.