Abstract: Dynamic performance of a novel vibration isolator made of reinforced foam plastics is investigated in this paper. Experimental results show that, under steady periodic excitation, the isolator has strong nonlinear hysteretic characteristics, the restoring force of the isolator is influenced by the exciting frequency and vibration amplitude and is relative with the deformation history, and the shape of hysteretic loops of the restoring force is related to the stiffness and damping characteristics in the isolator. In view of the characteristics, a new smart idea of modeling is presented. According to the energy analysis, the restoring force can be decomposed into conservative force and non-conservative force, viz. elastic restoring force and damping force. The study has proved the idea of modeling is an ingenious one, which provides a useful means for modeling and parameters identification of the isolator. It lays a good foundation for dynamic design and dynamic optimization of the vibration isolator. The presented method can also be used for reference for other nonlinear hysteretic system analyses.