Soil moisture dynamics and evapotranspiration of Caragana microp hylla communities with different ages were studied based on the soil water balance theory. Results showed that compared with natural C.microp hylla community,the soil moisture content of artificial vegetation was lower and continually decreased along with increase in age.The vertical change of soil moisture showed the tendency of increasing with soil depth in the 6-year-old and natural C. microp hylla communities,while performed a reserved trend in the 11 and 22- year-old C. microp hylla communities,and their soil moisture content in most layers were lower than 1.50%.Most precipitation lost through evapotranspiration during grow ing season and the temporal distribution of evapotranspiration had a single-peak curve.