Abstract: Based on the microstructure of the interpenetrating phase composites (IPC) with open-cell foam skeleton, a tetrakaidecahedron mechanical model with elastic foundation beam was proposed, and the prediction formula of elastic modulus was deduced using the minimum potential energy principle.The example analysis of experimental material parameters given by the literature was conducted.The results show that the present results agree well with the experimental results, which confirms the validity of this model.The influences of the volume fraction of different skeleton materials and the strut cross-section shape on the elastic modulus of IPC were discussed furthermore.The present semi-empiric theoretical model provides a new way for characterizing the elastic properties of IPC with open-cell foam skeleton commendably and a basis for the prediction of strength and thermo-physical properties of IPC.