Abstract:In order to investigate microphysical characteristic in the hailstorm, the dual polarization radar and raindrop spectrum data, with the hydrometer classification algorithm were used to analyse a hail weather occurred in Mount Tai on 1 June 2020, the distribution of the radar variable, hydrometer and the raindrop in the region around the Mount Tai station were obtained when the hailstorm cloud passed through the Mount Tai, the studies showed: 1) when the edge of hailstorm began to effect the Mount Tai station, the large gradient area of reflectivity (Z_H), which coinciding with differential reflectivity(Z_DR) arc position, was next to the Mount Tai station, the particles identified in Z_DR arc were mainly composed of abundant big drop, which was formed by melting graupel particles over Mount Tai station; the structure of the raindrop spectrum was double-peak, the greater contribution to precipitation is 2-3mm particles. 2) When the main part of the hailstorm cloud influenced the Mount Tai station, there occurred three-body scattering echo in radial front of the station and overhang echo over the station, the particles in the vicinity of the station were mainly identified as hail; on the south side of Mount Tai station there occurred the bounded weak echoSregion(BWER), the convergent ascending motion was enhanced in the BWER, which was semi-surrounded by the large value of Z_DR(Z_DR ring), the particles in Z_DR ring were mainly identified as big drop and hail, with small amount of graupel and wet snow; the contoured frequency by altitude diagram(CFAD) showed the ice phase process was enhanced, the hail particles under the -10℃ were mainly formed by the graupel particles between 0℃ and -10℃ layer riming the big drop and light rain particles carried by updrafts, these particles could not fall and collide to form larger precipitation particles during this period, therefore the structure of the raindrop spectrum became single-peak, the greater contribution to precipitation was 14-16mm particles. 3) When the hailstorm cloud left the Mount Tai station, CFAD showed the Z_Hcorresponding toSthe high frequency region decrease, the ice phase process was weaken, the efficiency of the cold cloud droplets attached to the ice crystals to converted into graupel was reduced, a large number of ice crystals and dry snow particles were identified above Mount Tai station, where the feature of the stratiform cloud precipitation appeared; big drop particles were formed by the melting hail, the structure of the raindrop spectrum became double-peak again, the second peak value of particles was 2-3mm, which contributed more to the precipitation.