A heavy drought caused by El Nio occurred in southwest China with higher temperature and less rainfall from October 2009 to April 2010.Statistics show that the affected area of farmland approaches 78% of that in-all China in corresponding period

and the number of affected population and livestock is up to the peak value in the last decade.This paper indicates that drought occurring in southwest China is not accidental

five provinces in southwest China had suffered dozen drought events simultaneously from 1951 to 1990

and drought had become more frequent in recent decades since 1949.This drought disaster is similar to that in 1963 in temporal and spatial distribution

cause of formation and loss.But from the viewpoint of meteorological drought

the duration of non-effective rainfall in partial area was 11 months in 1963

which is longer than corresponding 6 months in this drought.While the drought affected ratio and disaster-formative ratio of this drought are maximum since 1949.So the research shows that our society becomes more vulnerable to drought under the background of economic high-speed development.These conclusions are helpful to understand drought characteristics and evolution

and strengthen the construction of drought disaster prevention and reduction.