Abstract: The numerical analyses of vibration and sound radiation from a submerged elastic ring-stiffened double-shell with hemi-spherical cap on ends have been carried out by using FEM software ANSYS and BEM software SYSNOISE. The normal modes and its frequency response, surface sound intensity distribution and sound pressure and sound energy flow in near field, the radiated sound power and radiation efficiency of sound power are given when the double-shell Structure is immersed in water, excited by point force source. The directivity of sound in far field and the vibrational modes of this double-shell are also calculated.