The border of chernozem area in the Northeastern China has been discussed for a long time, but the view differed, and it would directly affect the zoning and the measure selecting in conducting "Soil erosion prevention and control project of chernozem area in Northeastern China". We try to expound the scale of the chernozem area in Northeastern China in a broad sense from the regional soil, geomorphology and economic structure. Some constructive suggestions on ecological construction of chernozem area are put forward in view of soil and water conservation.