In this study, cylindrical billets of Mg-3Al-1Zn (AZ31) alloy have been synthesized by spray forming technique. The alloy billets were hot-extruded into rods with proper processing parameters. The microstructures and mechanical properties of alloys were investigated. The results indicated that spray formed AZ31 alloys have a homogeneous and equiaxial grains with average grain size of 20μm. The further grain refinement with an average grain size of 5μm was attributed to the continuous dynamic recrystallization during the extrusion processing. The room temperature mechanical properties of the extruded rods are remarkably higher than those of as-cast AZ31 alloy. The average tensile ultimate and yield strength of the alloy are 321MPa and 237MPa, respectively, with an elongation of 15.2%.