Abstract： The deformation and energy absorbing characteristics and mechanisms of foamed aluminum with two different matrixes were investigated through examination of the compressive stress-strain behaviors. It was found that,like other porous solid materials, the stress-strain curve of foamed Al shows distinguished three regions, that is linear elasticity, plastic collapse or brittle crushing and densification. The energy absorbing capacity increases with increasing relative density, and brittle foam exhibits higher capacity than plastic one with the similar yield strength. Foamed Al reaches its peak value of energy absorbing efficiency at relatively lower strain, about 0.15—0.25. With increasing density, the peak values tend to decrease.