In this paper

a energetic physical variable——the generalized static energy is chosen

and the outputs of a two dimensional cloud model are utilized to the study of the atmospheric stability under conditions with and without cloud. The profiles of the generalized static energy and moist static energy are compared. The results show that the moist static energy is very different from the generalized static energy within clouds or in precipitation areas under cloud with the presence of liquid water and solid water. The generalized static energy is 13 J/g larger than the moist static energy in the planetary boundary layer.