Abstract: Using the matched data between the measurements of Tropical Rainfall Measurement Mission Microwave Imager (TRMM/TMI) and those of ground-based weather radar at Fuyang during the Intensive Observation Periods (IOPs) of GEWEX Asian Monsoon Experiment-Huaihe River Basin Experiment (GAME/HUBEX),the proper identification of rain area is obtained by the dynamic cluster classification method, and a passive microwave rainfall retrieval algorithm that rain rate is a function of the scattering index and the polarization corrected temperature at 85.5 GHz is established. The comparison between our retrieval test and the rainfall retrieval from the TMI and TRMM precipitation radar (PR) at the same time provided by NASDA of Japan shows that the algorithm used in this paper is successful in retrieving the distribution of rain rate and identifying the areas of rainfall over land.