Abstract: In the arid inland, evapotranspiration(ET) is the main way of discharge of groundwater and surface water. Accurate estimation of surface ET can provide the theory basis for reasonable exploitation and utilization of water resources and ecological environment protection in arid areas. Based on MODIS data, the regional ET of Ningxia Yellow River economic zone during the period of 2001—2014 was estimated using Surface Energy Balance System(SEBS) and the influencing factors of ET were analyzed in the meantime. Besides, the reliability of the ET results was validated using the principle of water budget. The results indicated that the annual actual ET of Ningxia Yellow River economic zone gradually increased from 2001 to 2014 with the value varying from 434.27 mm 2001 to 517.82 mm in 2014.The farmland ET is the major part of the total ET and agricultural water consumption accounted for nearly 2/3 of the regional water consumption. The result indicates that the SEBS ET is consistent with the value by water budget method, which is validated the reliability of SEBS model in regional ET estimation.