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利用美国国家环境预报中心NCEP 1971-2000年1月及2008年1月的再分析值高度、温度和风的气候平均场, 以及国家气象中心要素库中的2008年1月8日～2月6日08:00～08:00 24 h降水和冻雨实况等实测资料, 对2008年初我国南方的持续冰冻过程的异常成因做了分析.结果表明, 在稳定的高空环流形势下, 来自极地的冷空气和来自南支槽前暖湿气流及东海、南海的偏东气流交绥于我国大陆东南部, 加之稳定的滇黔静止锋、华南静止锋和近地面冷高压前东北冷平流, 多因素综合导致了这场罕见持续冰冻天气;冻雨出现在冷暖空气交界的锋区附近, 偏在能量锋区低值一侧.对流层中低层为西南暖湿气流, 强逆温层是冻雨天气突出的垂直特征, 贵州西部以没有融化层的“单层结构”为主, 贵州中部“单层结构”和“二层结构”均存在;湖南省西部冻雨垂直结构表现为“单层结构”和“二层结构”, 以“二层结构”居多, 东南部郴州的冻雨垂直结构主要为“三层结构”和“二层结构”.逆温层之下湿度很大, 逆温层之上湿度迅速减小, 干、暖空气有利于稳定层结, 抑制低层湿空气向上扩散, 对南方阴雨天气和冻雨天气的维持起了不可忽视的作用.“,”Using the mean climate fields of the NCEP(1°×1°) reanalysed height, temperature and wind data during January 1971-2000 and the observed meteorological element fields in our country from 8 January to 6 February 2008, the abnormal genesis of the frost and freezing weather process in Southern China in early 2008 are analyzed. The results show that under the stable upper air circulation situation, there are many factors leaded to the infrequent sustained freezing weather. These factors were the intersection of the cold air came from the polar and the warm and moist air ahead of southern branch westerly trough as well as the easterly flows from the East China and South China Sea, the stable Dian Qian stationary fronts and South China stationary front and the northeast cold advection in front of the surface cold high. Freezing rain appeared nearby the frontal zone of cold and warm air and it appeared at the low value region of energy front. The strong inversion layer is outstanding vertical features of freezing rain. There were mostly single-layer structure that without melting layer in west of Guizhou Province, and there were both the single-layer structure and two-layer structure in the middle areas of Guizhou. In west of Hunan, the vertical structure of freezing rain were single-layer structure and two-layer structure. There were high humidity under the inversion layer, and the moisture above the inversion layer were rapidly decreased. The warm dry air which were beneficial to stabilize stratification and inhibited upward dispersion of wet air in the low layer has an important effect on maintenance of rainy weather and freezing rain in southern.