Stainless Steel Metallic Pseudo Rubber (SSMPR) and Shape Memory Alloy Metallic Pseudo Rubber (SMAMPR) are novel porous materials with high elasticity and large restorable deformation, and they are also ideal material for three dimensional isolators or Shock Absorber Devices (SADs). However, the theories on the constitutive model of metallic rubber are seldom studied due to its complicated microstructure. A theory of contact micro-beams with equal section is presented in this study, in which the friction between the metal wires in metallic rubber is considered according to Coulomb's friction law. Firstly, the nonlinear rigidity of the micro-beams in the loading process is derived according to the simplified mathematical model. Then, the parameters in the theoretic model are also determined through establishing the relationship between the macro-structure and the micro-structure based on the law of mass conservation and the probability theory. Especially, the number of contact points between the surfaces of the micro-beams is estimated according to a mathematical function. Finally, combined with the finite element method, the results of normalized stress-strain relationships under compression are obtained and compared with the experimental data.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.