Improvement of tensile mechanical properties under dynamic loading has been demonstrated for a commercial magnesium alloy of AZ31. A commercial AZ31 alloy was subjected to simple shear processing through ECAE(equal-channel-angular-extrusion) followed by annealing to develop a different texture compared with the directly-extruded alloy. During the dynamic tensile test, elongation-to-failure was more than twice higher than that of the directly-extruded alloy. Inspection of the fracture surface on the dynamically deformed sample revealed that the ECAE processed alloy followed by annealing fractured with the development of ductile dimples and few macro cracks, which is often observed on the fracture surface of magnesium alloys.