Abstract: A new modeling method for a sandwich plate with viscoelastic material (VEM) layer is presented in this paper. It is difficult to process the dynamical analysis and control design by conventional methods because the constitutive relations of VEM are frequency and temperature dependent. As an example, the new modeling method, which combines the GHM (Golla-Hughes-Mctavish) method of VEM modeling and FEM (Finite Element method), is utilized to calculate the modal parameters of a cantilever sandwich plate with viscoelastic core. The results show that the new modeling method is more accurate and reliable than other methods and good agreement is reached in comparison with the test results and the simulation results of ANSYS5.5 and NASTRAIN70.7.