Abstract: Based on the analysis of the 500hPa geopotential altitude field and the anomalous field of the northern hemisphere between Nov.of 2008 and Jan.of 2009,it was found that the main reason for long-term shortage of rainfall in the city of Changzhi was that the sub high tension was stronger than usual above the west Percific Ocean,the line of regression slanting towards north and its location moving east off the usual in the same period,and the moisture transferred from the southwest sub high tension to the overhead of the city,unusually deficient.In addition,the continuously lasting unusual environment resulted in the successively serious drought.A detailed analysis of the influence on agriculture by drought in autumn and winter was given in this paper and a proposal was also put forwarded.

Key words: Drought, Climate characteristics, Analysis of reasons, The way to deal with in agriculture