The forced vibrations of viscoelastic packaging system under periodic excitations were investigated. The viscoelastic cushioning material of the system was assumed to obey the fractional derivative constitutive relation. Based on the dynamical equation, the dynamic characteristics of the critical component were studied. And the effects of structure parameters, such as the mass ratio, the frequency ratio and the damping on the amplitude ratio of system were discussed. The results may have important value for packaging design.