A severe hailstorm occurred near Dezhou, Shandong province on 28 June 2003. The synoptic situation, energy field and water vapor content field before the hailfall are analyzed by using the data of MICAPS, Rawinsonde observation and grid-point field from NCEP. The evolution process and the structure of the hail cloud are also analyzed on the basis of two Doppler weather radars. The results show that before hailfall, there is a tongue of high energy at the low level,and negative energy advection or a center of negative energy advection in the mid- and upper-level over the west of the hailfall area. The observation of Doppler radar showed that the supercell storm developed from a singlecell storm with the typical features of the supercell storm. Meanwhile, the moving direction of the supercell storm was about 20° in the right of its dominating wind direction, so it belongs to a right moving supercell storm.