Abstract: A model for the regional surface energy-balance and daily evapotranspiration is applied to the farmlands in the North China Plain,and the experiments at Luancheng Agro-ecosystem station,Chinese Academy of Sciences are made to test the accuracy of the model.The results show that the model can successfully estimate the surface daily evapotranspiration and the components of the surface energy-balance with the inputs of LANDSAT-7 Enhanced Thematic Mapper-Plus (ETM⁺) data and synchronous surface observation data at the experimental station.The frequency distribution of the daily evapotranspiration and the NDVI is different in different crop growing seasons,which is mainly caused by the different vegetation indexes.