Dual polarimetric radar has been developed and partly utilizedinmeteorology and hydrology in these twenty years because of its potential ability in estimating drop size distribution (DSD) and in discriminating precipitation type. Ministryof Infrastructure, Land and Transportation (MILT) in Japan put Shakadake operational C band Radar to practical use in 1992. However, large improvement had not been realized because of its initial technical stage. Under these circumstances, this study investigates observation precision of the latest C band polarimetric radar for promoting replacement of Japanese operational radars into operational polarimetric radars. As results, this study shows Z_HH Z_DR and K_DP observed bythe polarization radar well fit to non-parametricallycomputed Z_HH, Z_DR and K_DP using observed DSD, respectively. Also, this study shows "Radar observed ZDR-Dm of observed DSD" relation is consistent with observed DSD. Especially, K_DP, which is free from attenuation problem, is suitable to estimate the strong rainfall. Parameter from the polarimetric radar has high possibility to improve real-time rainfall estimation.