This paper makes use of the observational temperature data of the meteorological stations of the mountainous areas in North China and their respective latitude,longitude and altitude to establish a macro-earth surface temperature field equation for each mountainous area.Using the topographic map on the scale of 1:200000,and taking each 10'(longitude)×10'(latitude) as the step length,we inteapret the altitude value and place it into the established equation.After the topographic corrcction, the annual and monthly mean temperatures the annual range and the Σ t'≥10℃ of the mountainous areas in North China are calculated.The accuracy reaches a very notable level.The results make us gain a new recognition about the thennal resources of the mountainous areas in North China.Finally,the upper planting limits of the best species of the main fruit trees are calculated.