Crop water use (also know as evapotranspiraton, ET) monitoring is vital for agricultural management under the threat of water scarcity and global warming, as well as the pressure of increasing food demand. The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) has provided valuable high resolution ET estimates since its launch in 2018. Yet, evaluation of its capability in monitoring ET in the agricultural field is lacking, as well as the intercomparison of the two ECOSTRESS ET products calculated through different algorithms (PT-JPL vs. DisALEXI). This study focused on the agroecosystems and compared the ECOSTRESS ET to eddy covariance observations at 15 cropland flux sites in North America from July 2018 to December 2020. It is found that PT-JPL captured the diurnal pattern but tended to overestimate instantaneous ET in the morning. Besides, intercomparison of the magnitude, seasonal pattern and the dependency on crop phenology of ET from PT-JPL and DisALEXI revealed the higher fidelity of DisALEXI. The site-specific validations and visual comparisons with MODIS ET retrievals demonstrated the capability of PT-JPL and DisALEXI in identifying crop types and agricultural management practices to some extent. The heterogeneity of ET values in the small-scale agroecosystems highlights the importance of accurate representation of local conditions in the ET model.