Two experiments both of simulation under rainproof shelter and plot in field have been done to study the yieldresponse of corn to different treatments of water supply in Non-irrigated Plateau of Loess. The results show that,inthe field simulation column experiment,the biomass and the grain yield of corn are increased parabalically with theincreaseL of the soil moisture or the total water consumption, but the crop water use efficiency is hyperbolically de-creased with the increase of the total water consurnption, In the field plot experiment,the grain yield of corn is in-creased parabalically with the increase of the total water consumption too, the minimal crop water efficiency can bernade in the dry treatment, but the maximal crop water use efficiency can be rnade in the treatment of low watersupply(i.e,,the irtigation quota is 70 mm per Mu),with the increase of the irrigation(quota,the soil water depletionis decreased,and the percent age of soil water depletion in total is exponentially decreased.