Abstract: Mesoscale analysis was conducted on a severe hail event in Jianping of Liaoning, the physical parameters of the hail and impending warning indexes of radar were analyzed to provide reference for shortimpending warning of hail. Based on conventional meteorological data, Himawari- 8 data, Doppler weather radar data and NCEP/FNL reanalysis data, we analyzed the synoptic situation and mesoscale characteristics. The results showed that: with strong vertical wind shear, wind shear between 850 hPa and 500 hPa was above 90°, the temperature between 850 hPa and 500 hPa was higher than 26℃. There was hydrostatic instability. The hail happened in the initial development of strong convective cloud to mature stage, and at this time the cloud generally showed the texture and umbra. The TBB was less than -50℃ for a long time. When the hail happened, TBB value declined rapidly. The super cell storms were bow shape, which had the radar characteristics of inflow boundary and echo areas, it also had high reflectivity core, the reflectivity greater than 55 dBz reached to -20℃, VIL value was higher than 60 kg/m2 and VIL density value was over 4 g/m3, the everlasting mid- latitude cyclone maintained the vortex character in super cell. The results show the environmental parameter characteristics and threshold value of radar index, providing reference for shortimpending warning of hail.