An Mg–Li based alloy containing Sc addition has been prepared by melting and solidification in a carbon steel crucible, and extruded at a billet preheating temperature of 200C with an extrusion ratio of 28. Age heat treatments were performed to investiga An Mg–Li based alloy containing Sc addition has been prepared by melting and solidification in a carbon steel crucible, and extruded at a billet preheating temperature of 200C with an extrusion ratio of 28. Age heat treatments were performed to investiga