Yukiko et al. proposed a magnesium shape memory alloy which exhibits a super elasticity of -4.4% at -151°C and the heated shape can be recovered. The shape memory properties exhibited by this alloy result from reversible martensite transformation. This magnesium alloy contains light cerium and has an alloy density of 2 g/cm3, which is one-third lower than that of actual nickel-titanium shape memory alloys.