The time and space distribution of hail storms in Weihai City are analyzed with observational data and catastrophic events report from January 1960 to December 1997 at sampling stations and sounding data from January 1986 to December 1995 in Europe and Asia.Results indicate that seasonal variation of the Weihai hail storms exist a double peak value phenomenon.Hail storms are the most in May,June,September and October.Synoptic situation of Weihai hail storms demarcated cold vortex type,trough type,small trough type in northwest air stream and latitudinal trough type.In hail area,there is strong warm humidity advection along the boundary.There is labile stratification under midtroposphere.The humid area is of pack shape and the dimension is small.There is strong dry cool advection in the midtroposphere.The divergence is at the left side of exit over the mid and upper troposphere.