A novel dilute Mg–0.5Sn–0.7Al–0.8Zn alloy was developed and directly extruded after casting process. The extrudedalloy consisted of fine bimodal grained microstructure, local nano-precipitates micro-region and typical extrusion direction(ED)-tilted texture. A great balance between tensile properties (YS = 262.7 MPa, EL = 26.0%) and corrosion resistance(Pi = 1.57 mm/a) was achieved and discussed in terms of grain size, structure, orientation as well as precipitates and/or corrosionproduct film. As a result, this dilute alloy system shows the great potential to be developed as a biomaterial.