In recent years,the decreases of precipitation and increase of temperature in no rthern China appear which is known as the phenomenon of the aridification in nor thern China.In this paper,the relation between the decrease of annual precipitat ion and the increase of annual temperature is studied by use of an one dimension al energy equilibrium model in which the effects of advection is not included.Th e results are roughly in agreement with the realistic data.Meanwhile,we have als o investigated the magnitude of the increase of temperature in northern China in duced by the double of carbon dioxide from the one dimensional energy equilibriu m model which is around 1 ℃,roughly close to the result of numerical simulation ,showing the availablity of the application of this model in the research of ari dification in northern China.