Some investigations into the flexural vibrations of the ships' hulls are carried out. The author pointed out that such a higher mode of the hull vibration as which resonant to the propeller blade force excited through the hydrodynamic action is considered as the shearing vibration. The vibration profiles of the higher mode of the hull vibrations under some-assumptions of the distributions of the shear rigidity and of the mass are calculated based on the shearing vibration. Also, the natural frequencies of the fundamental mode up to the eight-noded mode of the vertical vibration of the cargo vessel, as an example, are calculated based on the shearing vibration with taking the corrections of the bending moment and the rotational inertia of the hull section into account. For the sake of realizing the requirement of simple method of estimation of the natural frequencies of the hull vibration including higher mode in the stage of the initial design, the empirical formula founded on the shearing vibration is presented. The empirical factors of the formula were determined based on the data which had been sent from the leading shipbuilders in Japan to the author.