Abstract: Several principles for designing the atmospheric model are suggested, namely, inclusion of the physical factors and physical mechanisms which can restrict the related atmospheric processes to possibly achieve the aim of the design; reasonable overall properties; stable and accurate computation; appropriate grid. resolution and computational domain and the various parts of the model being consistent. Also discussions are made for them respectively. Finally, special stress is put on the consistency between the design aim and the model, and the relative importances between factors and physical processes incorporated in the models with different forecast periods are discussed in detail.