Dynamic characteristics of underwater large shell of revolution are studied in this paper. Large rotational shell with optimum shape against hydrostatic pressure has a possibility of utilization for a storage of LNG or vessel of super conducting coil for power storage in the future. As one of many feasibility studies for the shell, dynamic characteristics are examined using numerical analysis, where finite elements for structure and boundary elements for surrounding water are used for the numerical analysis. Natural frequencies and modes of underwater drop shaped shell are calculated using the developed numerical code “DASOR” after vibration analysis of submerged cylindrical shell in order to justify the analysis for various water levels.