Abstract: An equivalent analysis method for sandwich shells made of composite materials is studied. The formulae of the interval forces and displacements of the sandwich shell are deduced from the shell theory.and by comparing the formulae with those of a single-deck anisotropic,hell the equivalent conditions are given for both shells. Therefore.the mechanic analysis of the sandwich shell can be converted to the analysis of a single-deck equivalent anisotropic,hell that is easy to solve by finite element method. At last an engineering example is computed. The results confirm the validity of this method.