中文摘要：

中国是一个农业大国,也是一个旱灾频繁的国家,研究气象干旱可为防范农业旱灾风险提供科学依据。利用1951-2011年中国585个气象站点的日降水数据,计算了不同季度的降水距平百分率,并确定气象干旱等级,编绘了各季节的中旱、重旱、特旱发生频率的空间分布图。结果表明：（1）我国各季气象干旱发生频率空间分布,总体呈现北多南少、西多东少的格局;春季和冬季发生频率较高、夏季发生频率最低,其中春季中旱和特旱的高频区面积占全国比例分别达到了46%和34.2%,冬季尤其是特旱高频区面积占全国比例甚至超过了70%,而夏季仅有中旱存在高频区,且面积较小;（2）华北地区的春季中旱,东部地区（四川除外）的秋季中旱,西南（云南）、华南（广东）、长江中游地区的冬季中旱,需重点防范。

英文摘要：

China is a agricultural country faced with frequent droughts.Studying on the meteorological drought offers some scientific basis for the prevention of the risk of agricultural drought.Based on the daily precipitation data of 585 meteorological stations during 1951-2011,seasonal precipitation anomaly percentages were calculated which determine the seasonal meteorological drought level.Accordingly the spatial distributions of occurence frequencies of all drought levels in different seasons were mapped.The results show：（1） China＇s meteorological drought bore a conspicuous character of uneven temporal and spacial distribution.The north and the west regions were faced with higher frequency of drought compared to the south and the east regions,and spring and autumn were the high-frequency periods for occurrence of the drought.（2） Middle-drought during the autumn in North and Northeast China,middle-drought during the winter in South China,Southwest China and the mid and lower reaches of the Yangtze River had higher frequencies of drought occurrence,which needs to be paid more attention.