Mg-1Zn-0.5Ca alloy was prepared by casting technology. The as-cast alloy was solution treated at 470°C for 24 h and aged at 175°C for 0-50 h. The microstructure, mechanical properties and electrochemical corrosion behavior of the alloys were investigated. The results showed that the average grain size of the as-cast alloy was 120-150 μm, and the precipitated phases were distributed uniformly in α-Mg grain. The as-cast alloy showed good mechanical properties. The tensile strength was 186 MPa, and ductility was 23%. A typical age softening responses was obtained during the aging treatment. In the electrochemical corrosion tests, corrosion of the alloys is improved in Hank’s solution and 3.5wt% NaCl solution after the solution and aged treatment. However, the aged treated alloys showed the better electrochemical corrosion resistance.