Base on the thunderstorm days,hail days and hail damage area data in east agricultural region of Qinghai Province from June to September from 1961 to 2010,the climate change trend,regressive analysis and significance test methods are used to analyse the tendency of thunderstorm days and hail days in recent fifty years.The natural variation tendency of hail days is forecasted with the optimum fitting value of thunderstorm days tendency as independent variable.The effect of artificial hail suppression under the background of climate change is qualitatively illustrated based on the significant difference between the tendency and natural trend of hail days.Meanwhile,the effect of artificial hail suppression is quantitatively analyzed based on the regressive analysis and significance test of the thunderstorm days and hail damage area.Results show that:1)The hail days has no an obvious decreasing trend from 1961 to 1990 under the same trend of background of climate change,therefore the artificial hail suppression effect is not remarkable.In contrast,the change trend of hail days from 1991 to 2010 decreases notably,with a significance level of 0.001,proving that the artificial hail suppression effect is remarkable. 2)There exists some fluctuations in some years,but the average rate of artificial hail suppression and mitigation is 52.6% with the 95% confidence level in east agricultural area of Qinghai Province from 1991 to 2010.