Abstract: The Polarimetric upgrades to NEXRAD radar (WSR-88D) and development of phased-array radar in USA are reviewed, the application of the two radars on watching and warning of severe weather are analyzed, especially in quantitative precipitation estimate (QPE) and hydrometer classification of dual polarization radar, tornado watching and warning with phased-array radar. The current status and development of dual polarization radar and phased-array radar in China are presented in this paper. This paper is value for application of these two kinds of radars.