Abstract: The study on soil moisture dynamic is instrumental in establishing the quantitative linkage between hydrologic dynamics and ecological patterns and processes.The experiment based on the auto-weighing lysimeters aims to study the soil moisture dynamics and evapotranspiration (ET) of revegetated and bare desert dune area.The results reflect that during the experimental periods between March 31 and October 21, 2002, the soil moisture dynamics is highly related to the individual rainfall events, the areas of Artemisia ordosica Krasch and Caragana korshinskii Kom vegetation have a grossly equal magnitude in overall ET through the growing period, and the daily ET is 1.31 mm/d and 1.22 mm/d, respectively.The soil moisture decreases greatly in the Caragana korshinskii kom vegetation during the non-rainfall time for more than one month, especially within the soil profile of plant root concentration depth of 40-60 cm and 100-140 cm.After a long time of intra storm period, the ET rate of Artemisia ordosica vegetation decreases from the former value of 1.8 mm/d to 0.9 mm/d, the corresponding values of Caragana korshinskii kom vegetation and the bare desert dune area are from 2.2 mm/d to 0.6 mm/d and from 1.1 mm/d to 0.4 mm/d, respectively.To the overall deep drainage from the bare desert area, it accounts for 113.4 mm.Hence, the order of magnitude of annual rainfall fraction (40.5%) turned into groundwater recharge for similar areas varies between 0 and 50%, which has been shown by some previous investigators.Consequently, the results of this study fit the situation in the high middle of this interval.The artificial re-vegetation uses this part of precipitation effectively by eliminating the deep infiltration.