Based on the S-band dual-polarization Doppler weather radar data of Jinan, combined with sounding and ground data, the evolution characteristics of storm parameters and ZDR column of two long-lived supercells are analyzed.The results show that the two processes have strong thermodynamic instability, medium or above intensity of CAPE and vertical wind shear from 0 to 6 km, which is conducive to the generation and maintenance of highly organized storms.The two supercell storms lasted for more than 4 hours, and the high reflectivity factor (≥60 dBZ) maintained for more than 3 hours, the average DBZM value was 65.8 dBZ, at the same time, both supercell storms had large C-VIL.The moving direction of the two strong storms is basically the same, but the difference of moving speed is obvious.The main factor leading to the difference of moving speed is the difference of guiding airflow of 500 hPa.The ZDR column is the ZDR high value area above the environmental 0 ℃ level and located in the strong updraft zone of the storm, indicating a small number of large oblate raindrops and a few horizontally oriented wet ice particles.The existence of mixed phase particles in ZDR column leads to low CC.The storm developed rapidly after the appearance of ZDR column and weakened gradually after the disappearance of ZDR column.ZDR column can be used as one of the early warning of hail.The appearance of ZDR column indicates that the strength and height of the updraft in the storm increase, which indicates that the storm will develop rapidly.The disappearance of ZDR column indicates that the intensity and the height of updraft in the storm will decrease, and indicates that the centroid of the storm will be reduced and the intensity of the storm will be weakened.The top of the ZDR column of the two storms is obviously different, but there is no significant difference between the top of the ZDR column and the height of 0 ℃ layer.