Ancient chronicles recorded that duriag the period of B.C. 1122-A.D. 220 saline-alkali soils occupied large areas along the sea coast of North China Plain. Inland saline-alkali soils were found in the northern part of the Plain, and also in the northern part of the Wei-ho Plain. In that period, amelioration of these soils were accomplished by using good irrigation-drainage system, by leaching, by rice planting and also by silting from periodical flooding water.