In this paper,the AMSU(Advanced Microwave Sounding Unit) data from NOAA-16 satellite are used in the simulation of the heavy rainfall event in the Changjiang-Huaihe River Valley during July 4—5 2003.When the atmospheric temperature,wind and humidity retrieved from the AMSU are added into the MM5 Adjoint Model,the initial fields are improved,especially in temperature and humidity.Compared with the simulation results from the MM5 model using only conventional observations,it is found that retrievals have ability to reveal clearly the structure of temperature and humidity fields,thus obviously improving the intensity and location of model precipitation,so that the accuracy of MM5 Adjoint Model’s rainfall prediction and its Ts grades are greatly improved.