The capacity of evapotranspiration is an important input part of hydrology model and its rational estimation has direct impact on the precision of runoff calculation.This paper built the dual-source potential evapotranspiration distributed model considering soil evaporation and vegetation evaporation with the input of daily LAI calculated by EPIC model in the upperstream of Huaihe basin. Based on the data of land use, meteorological and plant growth,the paper computed the capacity of evapotranspiration every grid with the size of 1km×1km from 2000 to 2008 and then made the correlation analysis between calculated value and measured value in three evaporation stations. The results revealed that the evapotranspiration capacity calculated by the model can better reflect the real capacity of evapotranspiration and can provide reliable evapotranspiration input for distributed hydrology model. The result can provide a new way for the calculation of evapotranspiration in Huaihe Basin and has reference value for other similar basins.