Abstract: In this paper Yellow River Delta is selected as the research area,and the temporal and spatial analysis method for water demand of crops is brought out which based on the regional evapotranspiration(ET) retrieval using remote sensing method with the help of meteorological data.Firstly,the remote sensing method based on surface energy balance equation which is a function of net radiance flux,soil heat flux,sensible heat flux and latent heat flux is used to retrieve ET.Five NOAA AVHRR images and one landsat TM image are selected to retrieve ET from July to September of 1999,and the ET retrieval map of TM is used to improved the spatial resolution of the ET retrieval map of NOAA AVHRR,so less TM images and more NOAA AVHRR images can be used to retrieve regional ET,which can improve the practicability of ET retrieval method based on Remote Sensing.Secondly,the ET retrieved maps of the 6 images combined to the reference ET result which is computed using meteorological data are used for the temporal and spatial analysis of total water demand of crops in different irrigation regions of Yellow River Delta from July to September of 1999.