The information of typhoon ‘Morakot’(200908) were observed by the X-band dual polarization Doppler radar on August 6～10, 2009. According to the moving path of the typhoon and different parts of the typhoon access to radar observation area, the observations of typhoon are divided into three parts, namely the spiral rain band region, the eye wall of typhoon and post-typhoon rain band. The changes of polarimetric parameters and spatial distributions of the dominant water particles during all parts of the typhoon are analyzed. The results show that the shallow convection exists in every part of the typhoon. Cold water and wet snow exist in every part of the typhoon and there also has a small amount of graupel and hail particles in post-typhoon rain band. The characteristics of melting layer of typhoon are obvious on the high ZDR, low ρHV(0) layers and high KDP layer exists in all parts of typhoon. The particle size in the eye wall of typhoon is smaller than the other two parts. The statistic results of polarimetric parameter show that the vertical distribution of ZH, ZDR and ρHV(0) are significantly different in three parts, however, the distribution of KDP has not obvious change in the different parts.