With the climatographies and MICAPS conventional weather charts from 34 meteorological stations from 1980 to 2004, the spatial and temporal distribution, circulation patterns, and moving paths of hail are analyzed．The results show that the eastern part of Chongqing had more hails than the western part，and the northeastern part had the most; the number of hail days varied unevenly in the past 50 years, with significant increasing after the 1980s; the intermonthly variation showed a doublepeak pattern, one peak between April and May and the other between July and August. Hails in Chongqing can mainly attribute to local convection, and then to systematic convection. The circulation background patterns for systematic convection can be divided into three types: vortex, northwest airflow, and upper trough, among which the northwest airflow is the major influencing system (accounting for about 62%). The moving paths of hails and some suggestions for improving the effectiveness of weather modification are given.