Abstract: According to the equation of motion in the elastic medium and integral equation of target scattering,the sound scattering from the elastic spherical shell with and without an inner plate is studied using the finite element and boundary element method, and the scattering normalized form functions of the shell with and without the plate filled with different volume of water are computed and the mechanism of resonance scattering is analYzed. The results show that the resonance of the shell with partially water-filled and without the plate is mainly related to the volume of water, and the resonance is caused by inner water and the spherical shell. The resonance characteristics of partially water-filled elastic shell with the plate are similar to that of vacuum structured elastic spherical shell, and the sound field in inner water is weaker which indicates the main resonance characteristics are decided by spherical shell and the plate. In addition, the scattering characteristics of spherical shell with plate and one side full water-filled are greatly different from the partially water-filled ones.