Based on soil erosion tests, this article analyses aspects of the problem of soil and water loss in the Yangtze River basin. These aspects include theories of soil and water loss, the basic course of soil erosion in sloping fields, the relationship between soil and water loss and river sedimentation, the basic theories of soil and water protection. Also, it is highlighted that soil and water loss in Yangtze River basin is serious, but is not strictly related to river sedimentation. The idea to "drain and protect soil" is put forward in place of the notion to "protect soil and water".