Abstract:Overall in 2009, the weather and climate are characterized by high temperatures and less precipitation. In this year, summer precipitation is the least in the past 10 years, regional and persistent drought was very significant, there is a serious drought in Huanghuai region and North China in winter. In summer and autumn, severe drought is monitored in the southwest of Northeast China, western Jiangnan, obviously drought in western South China and southern Southwest China. The typhoon number is significantly less than the normal generated over the South China Sea and the West Pacific. However, the number of landing China is more than normal, as well as the first landing one occurs earlier than normal. It is shown that the SSTA (SST anomaly) over the central and eastern Pacific was below normal before spring of 2009, and changed into a warm phase in April 2009. An El Nino event begins in June. Due to the influence forced by SSTA and interaction between ocean and atmosphere, the general circulation over the Northern Hemisphere is shown the dominant anomalies which have been characterized as respondence as follows: the intensity and position of subtropical high over the West Pacific vary more frequently than normal; the tropical convection in the warm pool of West Pacific is more active from winter to spring and near normal from summer to fall of 2009 compared to the normal; and the transition between meridional and zonal circulations is carried out by turns. The zonal circulation prevails in May over the mid high latitude area of Asia; the meridional circulation prevails in June, October and November. These may be the main factors that influence climate in China in 2009.