This paper presents experimental investigations and computational analyses on the elastic moduli of aluminum alloy foams under compressive and tensile loading and flexural vibration conditions. Experimental investigations confirm that the flexural moduli are significantly greater than the corresponding compressive/tensile Young’s moduli. Our analyses based on experimental results suggest this to be due to the difference in cell deformation mechanisms between uniaxial loading and flexural vibration conditions. Two dimensional finite element models with square-cell structure are proposed to clarify these phenomena. Their elastic moduli and cell-deformation mechanism under compression loading and flexural vibration conditions are observed. The results successfully clarify the effect of cell-edge bending in the discrepancy in stiffness.