Abstract:Based on the characteristics of hailing, characteristics of atmospheric circulat ion, physical quantity conditions, storm source and characteristics of radar ech o, five hailing processes in Zhangjiajie in 2005 were analyzed by using the NCE P reanalysis data, conventional data and ECMWF forecast products. The result sho ws that the hailing areas are distributed respectively in spots, lines and plane s, and the direct economical losses caused by different types of hailing processes have a significant positive correlation with the disaster stricken ar ea and disaster stricken population amount. The five hailing processes occur un der the typical upper air trough and northeast vortex hailing circulation backgr ound respectively, whereas those hails occurred in the upper air trough circu lation influence a larger area with greater destruction. Favorable hydrometeor c onditions, convective instability conditions and strong vertical wind shear prom ote the generation and development of strong convection synoptic processes. All the five storms occur in the location with a large gradient of topography, an d concentrate around mountains and the windward slopes in south of the mountain ous area, which means that the thermodynamic effect and landform play a critical role in the generation of storms and the development into hail cloud. All the h ailing processes have the characteristics of typical hail cloud radar echo, and the large hails with a diameter of about 2cm are generated during the four hai ling processes with the storm body VIL density of more than 4g?m-3, which means that VIL density has a significant indicating function for large hails.