Abstract: An advection aridity evaporation model,which includes the effect of advection on local evaporation,is introduced in this study to estimate farmland evapotranspiration of by Bowen ratio,the energy balance method.Results showed that the advection-aridity model can predict the evapotranspiration from winter wheat field very well.Besides,the model requires only meteorological date at one height in the farmland,so the model can be applied to practical use.