The micro-hardness and tensile properties of ECAPed and pre-ECAP pure copper were investigated by the Vickers micro-hardness and electronic tensile machine. Furthermore,the strengthening mechanism of ultrafine-grained copper produced by the ECPA was analyzed. The results show that the saturation of strain-hardening and strain-softening occurs in copper subjected to ECAP,namely,the flow stress is increased sharply with increasing in strain to the maximum value at 8 passes,and then tends to be saturated,which can be attributed to the saturation of grains size and dislocation density after ECAP. The mechanical properties of the ultrafine-grained copper can reach 400～410 MPa in tensile strength,12%～20% in elongation and HV140～146 in hardness. Tensile behavior of the ECAPed ultrafine-grain copper is described by the MA model.