There is a good correlation between vegetation typies and loess thicknesses in the loess Plateau with semiaridclimate. Forests are distributed in rock and thin loess regions in the Loess Plateau. Due to the higher porosity ofloess,related to effective soil moisture,precipitation is not able to penetrate into the loess deeply. Soil moisture in thesurfasce horizons losses severely under the semiarid climate conditions. Rehabilitation of vegetation may be by usingtrees or shrubs with deep roots in the rock and thin loess regiong and by using grsses or shrubs with shallow roots inthe thick loess region in the platesu.