A simple method to estimate the daily range of surface temperature is presented by using daily arbitrary time NOAA AVHRR Graph data based on the soil temperature equation which can express the daily variation of soil temperature.Particularly,the method can be applied in the calculation of inverse soil moisture so that when the both times of maximum and minimum temperatures are not consistent with the times that are required by thermal inertia method,this method can approximately estimate the daily range of surface temperature and can calculate thermal inertia of surface and soil moisture.In this paper,the feasibility is demonstrated using real cases.