Abstract: In the study of drought monitoring,the retrieve of soil and vegetation water content is processed respectively.For the influence of vegetation coverage on the earth's surface,it is difficult to obtain soil water capacity directly by optical remote sensing.Considering the spectrum reflectance of water,a new model named SWCI(surface water capacity index) which combined spectrum characteristic of both soil and water is proposed.Through the rainfall and soil water data of CMA,the model is consistent with the contents and changes of soil water,and very useful for the rapid soil water content monitoring in a large area.