Abstract:  The mathematical model of the hail disaster risk assessment was established, by using of GIS, to evaluate the hail disaster risk in Yunnan tobacco planting areas from three aspects such as sensitivity, risk and vulnerability, based on the relief degree of land surface, average hail days from May to September, the average GDP, the percentage of cropland, and the average production value of cropland. The results showed that the gradation of hazard evaluation for hail disaster was high in Qujing, Yuxi and Chuxiong, which should be pay more attention to defense hail disaster. The gradation was low in the southwest of Yunnan, including Simao, Lincang and Dehong, where the planting areas of tobacco could be increased. 

Key words: Hail disaster, Risk evaluation, Yunnan tobacco growing area