Mg-Li based alloys have been investigated for structural as well as for biomedical application. Mg-Li-Ca alloys show a low corrosion rate and a rather uniform corrosion layer. LZ21 shows a sufficient ductility for a fine-grained microstructure and comparable mechanical properties to ZX10 and WE43. The study offers to improve the understanding of the influence of corrosion on mechanical properties of LZ21, especially after high deformation, before and after annealing - preferentially a heat treatment temperature of 300 °C shows a good strength to ductility balance, even with small local corrosion.