Based on meteorological data generated by Kriging spatial interpolation, International Geosphere-Biosphere Program(IGBP)land cover data, and Normalized Difference Vegetation Index data observed by the Advanced Very High Resolution Radiometer(AVHRR NDVI), the potential evapotranspiration(PET)in the Hanjiang River Basin during the period from 2000 to 2006 was estimated with the Shuttleworth-Wallace(S-W)model. The results show that the spatial distribution of PET over the basin is significantly non-uniform, with annual PET values ranging from 496. 6 to 1 741. 8 mm/a and an annual standard deviation of 165. 9 mm/a. The non-uniform distribution of PET is mainly caused by local climate and vegetation types. PET changes seasonally with climate and the growth of vegetation. Input data with low resolution may homogenize the PET results to a certain extent in the same coverage. The density of the meteorological stations will affect the estimated results of PET. The density of meteorological data from Kriging spatial interpolation is much higher than that of the Climatic Research Unit(CRU)data. The spatial distribution and seasonal change of PET calculated using the Kriging interpolation data and CRU data were compared, and the results show that the PET data calculated using the Kriging interpolation data are more accurate than those using the CRU data.