Abstract: Based on the method of wave transfermatrix, the elastic wave and vibration localization in disordered periodicstructures is studied. A general formulation of the wave transfer matrix ispresented, and the localization factors of ordered and disordered periodicstructures are, respectively, calculated and discussed by using the method ofsingular-value decomposition. The method in this paper for solving theproblem of the wave and vibration localization in periodic structures canbe used in the optimization of this kind of structures.