Abstract: The double-stage isolator system has been used for vibration isolation and noise reduction in ship power plant for many years. In this paper, the sensitivity analysis method of structural vibration response with respect to design parameters of the double-stage isolator system is proposed. First, by using finite element method, the vibration velocity responses of hull＇s exterior surface are analyzed. Then, the sensitivity between velocity responses and design parameters of double-stage isolator system can be calculated based on the deduced structural sensitivity equations. The calculated sensitivity coefficients show the influence of the small change of design parameters on the vibration velocity. It can provide a theory foundation for optimum design and model modification of structure. The sensitivity analysis of structural vibration response shows that much valuable information can be obtained for the design of double-stage isolator system.