Abstract: To improve the accuracy of nowcasting and early warning for hail storm, we studied the environmental conditions and radar echo structure of a severe hail event in Guangxi in 2013 by using conventional observation data and NCEP reanalysis data and Doppler radar data. The results showed that: this severe hail event was caused by the 500 hPa plateau trough, the south trough, the low level shear line and the surface cold front; the strong positive vorticity advection in front of the upper trough, strong vertical wind shear between 0-6 km, strong and unstable atmospheric stratification stability, and the appropriate height of 0℃ and -20℃ layers were all conducive to the occurrence and development of hail storms; the severe hail storms occurred in the water vapor convergence zone; the typical supercell storm which had low level hook echo, bounded weak echo area, three body strong scattering (TBSS) and deep persistent mesoscale cyclone produced large hails. Thus, TBSS, 60 dBz echo extending to -20℃ layer and sustained longer time, the strong divergence at the top of storm can be used as indexes to identify severe hail storms.