(Mg66.2Zn28.8Ca5)100-xCux(at%,x = 0,1,3,and 5) bulk metallic glasses(BMGs) of 2 mm in diameter were prepared by the conventional copper mold injection casting method.Besides,the influence of Cu content on the microstructure,thermal stability,mechanical properties,and corrosion behavior of Mg-Zn-Ca BMGs was investigated.It is found that the addition of Cu decreases the glass-forming ability of Mg-Zn-Ca BMGs.Crystalline phases are precipitated at a higher Cu content,larger than 3at%.The compressive fracture strength of Mg-Zn-Ca BMGs is enhanced by the addition of Cu.With the formation of in-situ composites,the compressive strength of the Mg-Zn-Ca alloy with 3at% Cu reaches 979 MPa,which is the highest strength among the Mg-Zn-Ca alloys.Furthermore,the addition of Cu also results in the increase of corrosion potential and the decrease of corrosion current density in Mg-Zn-Ca BMGs,thereby delaying their biodegradability. (Mg66.2Zn28.8Ca5) 100-xCux (at%, x = 0,1,3, and 5) bulk metallic glasses (BMGs) of 2 mm in diameter were prepared by the conventional copper mold injection casting method. influence of Cu content on the microstructure, thermal stability, mechanical properties, and corrosion behavior of Mg-Zn-Ca BMGs was investigated. It is found that the addition of Cu decreases the glass-forming ability of Mg-Zn-Ca BMGs. The compressive fracture strength of Mg-Zn-Ca BMGs is enhanced by the addition of Cu.With the formation of in-situ composites, the compressive strength of the Mg-Zn -Ca alloy with 3at% Cu reaches 979 MPa, which is the highest strength among the Mg-Zn-Ca alloys. Morerther, the addition of Cu also results in the increase of corrosion potential and the decrease of corrosion current density in Mg-Zn -Ca BMGs, thereby delaying their biodegradability.