This paper treats the transmission of the vibrational waves in periodical structure. Main results are as follows. 1. We propose a method for a vibration analysis of a periodical structure, using a simplified expression of n-th power of transfer matrix. 2. We explain a vibrational behavior of semi-infinite periodical structure, employing the fact that the characteristic equation of the transfer matrix is inverse equation. 3. Experiments were carried out to compare with the theoretical calculation. In general, they were fairly in good agreement.