Abstract: Analyze the characteristics of spectral dispersion for submerged cylindrical shell structure under the various hydrostatic pressures. The laws of changing with the various water-depth effects on the indefinite cylind rical shell vibration is researched. The coupled vibration equations of the submerged shell under the hydrostatic pressure are derived by Fltigge shell equations and Helmhohz equation. The coupled equations are solved by Muller method, and therefore the spectral dispersion characteristics are obtained. The results show that the hydrostatic pressure will influence the dispersion characteristics of submerged shell, and its effects will add by the increased of water-depth. By the comparison with the reference 4 results,it indicates that hydrostatic pressure has little effect on the initial frequency of the propagation wave,but is apparent on the subsonic waves above the acoustic velocity curve. The numbers of corresponding waves will decrease with the increase of waterdepth ,as the water-depth increasing by equal spacing, the more of submerged depth increased, the more of effects will be added ,and the space between the curves will be increased as well.