Abstract: In this paper,the concept of transfer matrix and altenate computation scheme of matrix power product is used to analyze free vibration of struct-ures for tall buildings.The structure is composed of identically constructed Story units,and closed form solutions are deriveld.For different story uni-ts of structure,the theory of structural perturbations is used.The correct calculation formulation of free vibration frequency is obtained.The method is very simple and has batter calculation precision,which can be applied to computation frequency and normal modes of structure. Finally,numeric-al example is made as such.