Abstract: In order to find a technique that can obviously improve the strength of magnesium-lithium alloy,an alpha-beta biphase coexistent magnesium-lithium alloy was designed according to the Mg-Li phase diagram and the effect of Al.The alloy was extruded and rolled.The microstructure and properties of the alloy in different states were systematically investigated by optical microscope and XRD.The results show that the microstructure of as extruding-rolling at 300 ℃ is satisfying.The dynamic recrystallization proceed comparatively completely.The grain size become relatively uniform.The second-phase particles regularly distribute at the grain boundaries.The tensile strength and elongation of the alloy respectively reach 280 MPa and 13%,which indicates that it has relatively high strength and good plasticity.