The as-cast and as-extruded Mg-14 wt％Li-xSr (x=0.14,0.19,0.39 wt％) alloys were,respectively,prepared through a simple alloying process and hot extrusion.The effects of Sr addition on microstructure and aging behavior of the Mg-14 wt％Li-xSr alloys were studied.The results indicated that β(Li) and Mg2Sr were the two primary phases in the microstructures of both as-cast and as-extruded Mg-14 wt％Li-xSr alloys.Interestingly,with the increase of Sr content from 0.14wt％ to 0.39wt％,the grain sizes of the as-cast and as-extruded Mg-14wt％Li-xSr alloys markedly decreased from 5000 μn and 38 μn to 330 μm and 22 μm respectively,while no obvious changes of the micro-hardness and microstructure of the as-extruded alloys were observed during the aging treatment.