The comparison between the cold vortex with the large area hail shooting process on 13 June 1996 and that without hail shooting on 20 June 1996 was c(3nducted. In addition to obvious difference of upper air circulation at north of the vortex, the significant differences in between were manifested on low-level wind field,temperature field and stability. If the ridge of high at north of the cold vortex over north China is extending forward northeast, there will be a northeast flow entering the rear of vortex along the front of the ridge. Meanwhile in the low level there is a obvious east-west frontal zone around 40°N with deformation field of frontogenesis, which approaching to the potential unstability area in northwest of Shandong province,the cold vortex will cause a large area hail shooting. Otherwise if the upper cold vortex developed into a symmetrical and deep cyclone,no hail shooting will occur in Shandong at the south of the cold vortex.