The equations of motion for a three-layer sandwich circular plate with viscoelastic core are derived. The Donnell-Mushtari-Vlasov assumptions follow to simplify. For the case of iso-symmetric annular plate, ΓΏve equations are further reduced to three equations. The assumed-mode method then yields the free and the forced solutions being characterized by six generalized coordinates for each circumferential wave number n. Due to the splitting of transversal and in-plane terms the study of vibration response can be reduced to the consideration of the SDOF linear oscillator with hysteretic damping. Numerical results ΓΏrst illustrated the frequency response function (FRF) for two di erent visco models and slight di erence is observed. The e ects of frequencies changes and damping due to viscoelastic material (VEM) core for several core-to-face thickness ratios are studied. The results, via the FRF's, show that a relatively thin visco (VEM) core can reduce vibration e ectively, but as the core thickness exceeds it the damping gradually reduces. The embedded VEM core decreases the frequencies as expected. The damping e ects upon individual modes are looked into as well. The results show that the n = 0 mode is a ected the most by VEM core.