Abstract: According to water balance theory, we study the soil moisture content and the evapotranspiration of Caragana microphylla plantation in different ages and density to ascertain the suitable configuration of the artificial Caragana microphylla sand fixation plantation in west Horqin Sandland.The result shows that the Soil moisture content is continually decreasing along with the increase of the ages and the density of the artificial sand-fixed vegetation.The soil moisture content of the artificial Caragana microphylla sand-fixed vegetation is less than that of the floating dune and the savage vegetation.There is remarkable positive correlativity between evapotranspiration and rainfall.The soil moisture content of 4 years old with 1m×1m density and 19 years old with 2 m×2 m density plantat ion is above wilting humidity, the soil moisture storage has surplus in the end of growth phases, and the soil moisture content can meet the needs of the plantation growth.We suggest that keeping 1 m×1 m density in infancy time and 2 m×2 m density in autumn by thinning techniques while establishing Caragana microphylla sand fixation forest.