Using the fifthgeneration PSU/NCAR Mesoscale Model (MM5V3.7), a rain storm on June 25 to 26, 2005 in Henan Province is successfully simulated. The output of the model such as integrated hydrometeor, the Doppler Radar echo, and the 24ho ur precipitation are very the same like the fact. Based on the good res ults of the model, the dynamic and thermodynamic conditions, the changes of the i nstability index in two different areas and the hydrometeor changes are analyzed . Besides, the differences of the microphysical structures characteristics in the different phases of the precipitation process are analyzed by using the quality content of snow (Qs), graupel (Qg), ice (Qi), rain (Qr), and cloud water (Qc) calculated by Reisner microphysical schemes.