Deformation behavior of metallic foams is complicated due to changes in bulk density and volume during deformation. In the previous studies, repeated compression tests were conducted with cylindrical specimens of open-cell type nickel foam and closed-cell type aluminum foam to investigate changes in density and dimensional change. In this study, Oyane’s yield criterion which was originally developed for powder sintered materials and the associated flow rule were used to describe the deformation behavior of the metallic foams with consideration of changes in density, i.e., volumetric strain. The material constants in Oyane’s equation were determined for the two metallic foams based on the experimental results. The obtained constants were a = 2.12 and m = 0.3 for the both foams. Deformation behavior in uniaxial compression is successfully reproduced with the obtained material constants.