Abstract: The vegetation index and crop canopy temperature were calculated respectively by using reflectance of FY-1D/AVHRR Data Channel 1 and 2 and brightness temperature of Data Channel 4 and 5,moreover,vegetation supply water index was calculated to monitor drought condition.The article had introduced sententiously the method that vegetation supply water index to monitor drought condition in Inner Mongolian. It showed that method of vegetation supply water index is fit for drought monitoring during vegetate stage in large scale.