Two-dimensional (2D) random cell models composed of circular cells with different sizes are developed to simulate the microstructure of silicone rubber foams. The two-parameter Mooney-Rivlin strain energy potential model is employed to characterize the hyperelasticity of the solid of which the foams are made. Finite element method is used to simulate the large deformation of the foams. Predicted uniaxial compressive stress-strain curves exhibit universally three deformation regions: an initial linear-elastic response, an extended plateau region, and a final densification stage as cell collapsing. It is also found that with the foam relative density increasing, the initial linear-elastic region is found to extended, the buckling plateau section becomes indistinctive, and final densification stage is hastened.