According to the hail data of the recent 40 years(from 1962 to 2002) over Qinghai Province,the temporal-spatial distributional characteristics of the hail disaster occurrence frequency,disaster area,and disaster rate are studied. The result shows: The frequency of hail disaster occurrence increased gradually from the 1960s,reached the peak in the 1980s,and decreased gradually from the 1990s.Hail disasters occurred in Qinghai Province from May to October,mostly in June,July and August.The hail disasters occurred in the northeastern part accounts for 86.35% of total hail disasters.The high-frequency hail disaster area did not overlap with the high-frequency hail event area.The hail disaster area increased gradually also over the whole province,basically in agreement with the tendency of the hail disaster occurrence frequency.There is intermonthly variation in the average disaster area and disaster rate for all parts of Qinghai Province,with the maximums of the disaster area and disaster rate in July and September in the northeastern Qinghai,and those of both disaster area and disaster rate in July for the southern Qinghai.The diameters of hailstones inducing disasters appear between 20 and 30 mm mostly.Both disaster area and disaster rate increase with the increasing hailstone diameter.When the diameters of hailstones exceed 40 mm,crops will be damaged destructively.