The commercial pure Mg, AZ31 and AZ61 alloys were severly plastic-deformed through equal channel angular pressing (ECAP). The grain size of pure Mg was decreased from 400 to 80 μm after ECAP and the 4 ECA pressed AZ31 alloy revealed the mixed microstructure of fine grains of less than 5 μm and coarser grains of approximately 5∼10 μm. Newly formed grains were attributed to dynamic recrystallization during ECAP at temperatures of higher than 1/2 T_m, where T_m is melting temperature. There was small increase of microhardness, yield stress and tensile strength in the ECA pressed pure Mg, while those of AZ31 and AZ61 alloys drastically increased after 1 pressing. The yield stress in the ECA pressed AZ31 and AZ61 alloys gradually decreased with increasing the number of pressings, but the tensile strength increased slightly. In particular, there was a typical tensile characteristic when compared with the other ECA pressed metals; a marked improvement in elongation was found concurrent with the pronounced strain hardening, without sacrificing the tensile strength, in the 4 ECA pressed AZ31 and AZ61 alloys. These tensile deformation characteristics were explained based on the observation of the deformed microstructure in the vicinity of fracture surface.