Abstract: Measurements show that dynamic characteristics of the rubber isolators relate to excitation amplitudes and excitation frequencies. A model characterizing the relations between excitation frequencies as well as excitation amplitudes and the dynamic performances of a rubber isolator are presented. The amplitude dependency is characterized by adding friction effects and the frequency dependency is included by a viscoelastic fractional derivative element. The estimated dynamic characteristics of the rubber isolator using the proposed model are compared with those estimated using two frequently used models (models based on a Maxwell model and a Dashpot model). A single-degree-of-freedom system with a rubber isolator is used to calculate the response of a mass under the free and step excitations when the rubber model is characterized with the proposed model and the Kelvin-Voigt model, respectively. The calculated results show that the proposed model is efficient over the two frequently used models in estimating the frequency-and amplitude-dependent dynamic characteristics of a rubber isolator. Thus the proposed model can be used to analyze dynamic response of a system with rubber isolators.