Foamed aluminum has been applied in many fields due mainly to its excellent properties. The tensile deformation process and characteristics of foamed aluminum with closed-cell were studied in this paper and the deformation mechanisms were discussed. The results show that foamed aluminum fractured without necking. The tensile stress-strain curves have similar characteristics, the linear elasticity at a low stresses followed by plastic yielding, strain hardening and rupture, which has obvious difference with compression stress-strain curve. The fracture mechanism is neither brittle fracture nor plastic fracture. The defects existed in foamed aluminum interior have important influence on tensile property.