The impact of soil loss on the deterioration of soil fertility on loessplateau is mainly displayed in the lossing of ecological function of agriculture, forestry and husbandry, the damage of soil resource,zonal soilreplaced by unzonal soil, resources worsend, the cycle system of soilmatter damaged as to a great amount of nutrients lost, the ratio ofproduction to input unbalanced and soil quality lowered, all thesethen induced arid and poor consequences. The reserving way is suggestedas follows, 1.to utilize the land rationaly and build the protective agriculture being a composited body of agriculture, forestry and husbandry toenhance virtuous cycle,2.to control slope as quickly as possibe,to improveagricultural production condition and construct highyield farm land, 3.toincrease the input of organic and inorganic matter to strengthen theefficiency of matter cycle or to set a virtuous cycle system of ecologicalagriculture.