In order to study the connection of microwave brightness temperature and precipitation, a new statistical retrieval algorithm is built by the stepwise regression method with wellmatched precipitation radar (PR) data and TMI brightness temperatures data. The results show that for the precipitation of 0.1 to 3 mm/h and 3 to 6 mm/h, the retrieved results correlate well with the retrieved precipitation from PR radar; for precipitation of 6 to 10 mm/h, the correlation is poor; and for precipitation over 10 mm/h, the correlation is well, but the rootmeansquare error is big, which means that the method can be used to predict strong rainfall centers with smaller retrieved values. With the method, the heavy rainfall process happened on 18 July 2004 is successfully retrieved. The results show that the spatial distribution of the rain belt and the location of the strong rainfall center are consistent with the retrieved precipitation from PR radar and Doppler radar.