Based on data of soil moisture in field experiments of the water irrigation which have been conducted in the Luancheng Agriculture Experimental Station of CAS, SWAP(Soil-Water-Atmosphere-Plant) Model developed by Wageningen Agricultural College was used as an analysis tool. The parameters in the model were calibrated with the data of irrigation experiment. It is of a great significance to know field evapotranspiration and establish reasonable irrigation scheduling and improve ecological environment. The m...