Mg-2.58 Gd-1.32 Dy-0.12 Zr and Mg-10.94 Gd-4.98 Dy-0.13 Zr（mass fraction）alloys were prepared by pure purification and smelting technology.The phase constituent and microstructure

microhardness

room temperature tensile and compressive performance of as-cast alloys prepared were analyzed by X-ray diffraction

metallographic microscope and scanning electron microscope

micro hardness tester as well as universal testing machine.In addition

the pH value was measured to evaluate the corrosion resistance of alloys in simulated body fluids

and the blood compatibility of alloys were investigated by hemolysis test

meanwhile

cytotoxicity of alloys was determined by MTT method.The results reveal that the microstructure of as-cast Mg-2.58 Gd-1.32 Dy-0.12 Zr is composed of onlyα-Mg phase

while the microstructure of Mg-10.94 Gd-4.98 Dy-0.13 Zr alloy is composed ofα-Mg matrix and a small amount of Mg5 RE second phase.The microhardness

tensile strength and compressive strength of the as-cast Mg-10.94 Gd-4.98 Dy-0.13 Zr alloy are superior to those of the Mg-2.58 Gd-1.32 Dy-0.12 Zr alloy.The corrosion resistance of as-cast Mg-2.58 Gd-1.32 Dy-0.12 Zr alloy is better than that of Mg-10.94 Gd-4.98 Dy-0.13 Zr alloy.The hemolysis rates of Mg-2.58 Gd-1.32 Dy-0.12 Zr and Mg-10.94 Gd-4.98 Dy-0.13 Zr are lower than5%

which dosen’t cause hemolysis.The cytotoxicity of Mg-2.58 Gd-1.32 Dy-0.12 Zr and Mg-10.94 Gd-4.98 Dy-0.13 Zr reach level 1

presenting cytotoxicity-free.