Densification behavior of various metal and ceramic powder was investigated under cold compaction. The Cap model was proposed based on the parameters obtained from axial and radial deformation of sintered metal powder compacts under uniaxial compression and volumetric strain evolution. For ceramic powder, the parameters were obtained from deformation of green powder compacts under triaxial compression. The Cap model was implemented into a finite element program (ABAQUS) to compare with experimental data for densification behavior of various metal and ceramic powder under cold compaction.