Abstract: Precipitation plays a decisive role,in the maintenance and stabilization of the ecosystem in arid zones.This paper uses geostationary meteorological satellite and ground meteorological data and the Chinese energy water balance monitoring methods to monitor plant environment changes to provide a scientific basis for land desertification dynamic change research in China. Since 2000,the annual average precipitation has in creased in most areas of northern China,the climate is generally warm in arid regions and the ecological environment has improved in some areas. In arid region of North China for nearly 10 years precipitation has slightly risen. The soil moisture index and the precipitation tendency is consistent and the ecological environment is relatively better. In eastern Inner Mongolia,Alashan plateau and Hexi Corridor,precipitation and soil moisture index have slightly increased,increased obviously in northern Qinghai.

Key words: drought, precipitation, desertification, arid zone of northern China, trend