Water is the key factor for stable yield and improvement of the agricultural ecosystem in Mu Us sandland.This study investigated the spatiotemporal patterns of soil water variations.The results show that the ways by which soil water escapes increased when the ground was covered by vegetation,especially,the vegetation transpiration influenced soil water substantially through gradual loss.The bare ground showed opposite results.Along with the thickening of dry sand layer,its protection on soil water from loss became more and more visible,and the soil water in deep layers recovered considerably in the latter stage.Considering the protection by the dry sand layer,soil water consumption of vegetation covered land was higher than that of bare field.Clearly,the invalid evaporation on bare surface could not be neglected.Therefore,to recover the agricultural production and vegetation on land of desertificated regions,the ground surface should be covered for reserving soil water as potential water supply.In addition,the understanding of soil water movement in sand field can provide theory evidences for efficient water usage and management for agricultural production in similar fragile regions