Abstract: Ultrafine-twined pure copper was prepared by asymmetrical accumulative roll-bonding (AARB) and followed recrystallization annealling. The one-way tensile properties and the fracture behavior of the copper after AARB and recrystallization annealling were investigated by tensile test and scanning electron microscopy (SEM). The results show the tensile strength and breaking elongation of pure copper deformed by 6 passes in AARB were 543 MPa and 5.67%; after the recrstallization annealling treatment at 240 ℃ for 40 minutes, the ultrafine-twined copper achieved 546 MPa in tensile strength and 7.31% in breaking elongation. The bonding mechanism of AARB deformation was crack bonding. Rolled after 6 passes AARB, the failure mechanism of copper was hole-joining fracture; and the fracture morphology of ultrafine-twined copper after recrystallization annealling was composed of dimples and cleavage steps.