Foam silicone rubber is a typical porous material whose constitutive behaviors are attributed to the hyperelastic properties.A porous media model is introduced for a description of foam silicone rubber. In view of the hyperelastic constitutive features and the induced compressibility of material due to porous structural characters, the influences of porosity on deformation behaviors are investigated and the isochoric part and volumetric part of strain energy density function is built up. Uniaxial compression experiment demonstrats that the obtained constitutive relations works well to describe the mechanical properties under large deformation of foam silicone rubber.