Abstract: First in this paper, we deduced the equations relating the precipitation with the air temperature and ground temperature from the vapour balance equation of the atmosphere and the heat balance equation of the earth-atmosphere system. And then based on the heat conduction equation of the soil we obtained the ground temperature prediction equation and hence designed a model for long-range precipitation prediction. According to the real data we also have estimated the orders of the equations parameters which are related to the climatological normals. Based upon this estimation we simplified the model reasonably and finally obtained a practical model for long-range numerical precipitation prediction.