he objective of this study is to build soil water supplement model. The characteristic of the model is the couple of the daily average transpiration coefficient and the subsection ratio of leaf transpiration and soil evaporation, while the coefficient and the ratio are often assigned to constant values during crop growth and development period in past studies. The model is used to quantitatively calculate the amount of evapotranspiration and soil water supplement during the whole growth period of winter wheat of Guanzhong Plain during 2007—2008 by using the remotely sensed and dynamically simulated LAI and biomass. The pointbased verification show that the results are accuracy when fully access to the information of rainfall and irrigation conditions. According to the spatial distribution of the soil water supplement, the soil water supplement in the whole growth period of winter wheat gradually decrease from the northwest to the southeast in Guanzhong Plain, which is roughly consistent with the variation trend of the water stress level in study area. In addition, the soil water supplement calculated by model in 2000—2001 reveal the possibility to obtain a more accurate result if we can get more high quality remotely sensed data, especially which are during the main growth period of winter wheat. All the results confirm that the feasibility of using this model to retrieve the soil water supplement throughout the growth period of winter wheat.