Abstract: Based on SEBAL model,the daily evapotranspiration of Sanjiang Plain in Northeastern China was estimated by using MODIS/TERRA products and meteorological data collected in meteorological stations distributed over the study area.The estimation results of June 22nd,2005 was taken as an example in the analysis of daily ET characteristics of different land covers in the study area by using the spatial analysis module of ArcGIS.Comparison of the evapotranspiration estimated with MODIS products and field observation showed that the average relative error was 11.2%.It was concluded that evapotranspiration of water body and forest were high,which were 8.2mm and 6.5mm respectively.They were followed by wetland and paddy field,which were 5.2mm and 4.8mm respectively.Evapotranspiration of dry land was lowest,which was 3.7mm.Basically,these results were in line with the rule of evapotranspiration.

Key words: Evapotranspiration, Evapotranspiration, Energy balance, SEBAL model, MODIS/TERRA products, Sanjiang Plain