By using hail data at 148 stations in Sichuan Province during 1978—2007, the spatial and temporal characteristics of hail days were analyzed. The results show that hail days are more in plateau and mountain areas than basin areas. The number of hail days has declined as a whole, especially in plateau areas. The hail appeared with the highest frequency in summer, less in spring and autumn, and the least in winter. In the interannual variations, the periods of quasi biennial oscillation and 6 year oscillation are primary. The similar inter monthly variation in hail days happened to the surrounding stations which have the similar altitudes.