Actual evapotranspiration is one of the most important components of hydrology for water managers. Given the importance of this parameter, measuring of that is facing with many restrictions. But by developing of remote sensing sciences, the spatial and temporal problems can be largely solved. The aim of this study is estimating the actual evapotranspiration of Pistachio trees in Rafsanjan plain. In this study, the MODIS satellite images and SEBAL algorithm are used to estimate the rate of actual evapotranspiration in water year of 1387-1388. Then, due to lack of observational data for evapotranspiration, the estimated reached from satellite images was compared with daily potential values of Penman-Monteith FAO56 and also was compared with monthly values of evaporation pan data and reported amounts by national water document of Iran. Finally these values within the obtained amounts of evapotranspiration from balance area were pursued. It is worth noting that first of all the flowchart algorithm used in this research was validated and calibrated by use of observational electronic weighing lysimeter data located in Shahid Bahonar University field. In Rafsanjan plain, results showed that the rate of evaporation of pistachio orchards in year of 2008 was about 502.32 mm. this amounts of evapotranspiration indicates that pistachio is almost suitable for the region but it seems due to lower rainfall, the only factor of the underground water level reduction is digging illegal wells to increase cultivation areas.