According to the distribution characteristics of heavy metal elements, nutrient elements (varied quantities of elements for agricultural benefits) and healthy elements in surface obtained from multi-purpose regional geochemical survey in Zhangye-Yongchang area, in combination with features of the landform, soil types and geological characteristics, and with the content grades of pollution elements affecting soil environmental quality (non-pollution, slight pollution, moderate pollution) as the major partitioning basis, the authors divided the whole region into high quality agricultural area, medium quality agricultural area and low quality agricultural area. Among them the high quality agricultural area was further divided into five subareas, which cover an area of 691.83 km ², accounting for 19.66% of the whole surveying area; the medium quality agricultural area was further divided into three subareas, which cover an area of 5 799.49 km ² with widest distribution, accounting for 67.38% of the whole surveying area; the low quality agricultural area was further divided into three subareas, which cover an area of 1 116.10 km ², accounting for 12.96% of the whole surveying area.