Abstract: Based on the experimental data of uniaxial compression and stress relaxation,stress relaxation model of five parameters of compressible silicone foam was obtained by using least square method.Utilizing the constitutive relation,the nonlinear viscoelastic constitutive model was applied to simulate the viscoelastic behaviors of porous silicone cushion in composite structure,and the pattern of stress relaxation of the cushion was obtained in process of short-time.A comparison was carried out with the data of uniaxial compression relaxation experiments.The results indicate that the experiment shows good agreement with theoretical results,and the constitutive models can predict the relaxation characters of silicone foam materials.