Abstract: In this paper, the sound radiation sensitivity of thin plate is studied by using FEM and sound radiation mode method.The velocity distribution of structure is solved by FEM and the surface sound pressure is computed by Rayleigh integral respectively.Then, the sound power can be expressed as a positive definite and Hermitian.Finally, the sound radiation sensitivity can be expressed as sensitivities of the impedance matrix and the velocity of plate by derivation of sound radiation power with respect to design variables, which can be solved by sound radiation mode theory and FEM.Taken a simple supported thin plate as a simulation example, the simulation results show the validity of the presented method.