Abstract: The effects of different Zn contents（0-0.6wt%） on the microstructure and mechanical properties of rolled Mg-1Al-0.3Ca-0.3Mn magnesium alloy sheet were studied by optical microscope（OM）, scanning electron microscope（SEM）,X-ray diffraction（XRD） and universal testing machine. The results show that the addition of appropriate amount of Zn can effectively refine the grain and improve the microstructure of the alloy. With the addition of Zn, the yield strength and elongation of the alloy are greatly improved. When Zn content is 0.4wt%, Mg-1Al-0.3Ca-0.3Mn alloy shows the best mechanical properties, with tensile strength of 264.4MPa, yield strength of 240.9 MPa and elongation of 20.75%. The addition of Zn element produces fine grain strengthening and solution strengthening effects in the alloy.