The loess region lies in the middle reaches of Huung He River. The water-holding capacity, evapotranspiration, water deficit in soil, infiltration of rainfill into soil and the dry layer for soils in the loess region are investigated in this paper and their effect on ecological environment is also discussed.The soils in most of the loess region have a waterholding capacity of 250mm per metre of soil layer. The annual evapotranspiration corresponds approximately to annual average precipitation for the fields...