In order to improve the glass forming ability of Mg-Zn-Ca alloy, 2mm and 4mm rod samples of Mg-Zn-Ca-Sr alloys with different amount of Sr were prepared by copper mould injection method. Effects of Sr addition on glass forming ability and corrosion properties in simulated body fluids of Mg-Zn-Ca alloys were studied by means of X-ray diffraction, scanning electron microscopy, differential scanning calorimeter and electrochemical test. Results showed that with the increasing content of Sr element, the 2mm rod samples were all in completely amorphous state. While the microstructure of 4 mm rod samples were composed of amorphous phase and crystalline Mg and MgZn phases. However, the volume fraction and particle size were decreased with increasing addition of Sr element, which indicated that the glass forming ability of Mg-Zn-Ca alloy was enhanced with Sr element addition. Mg65Zn30Ca4Sr1 alloy exhibited the highest glass forming ability. The results of electrochemical test demonstrated that Sr-doped samples showed more positive corrosion potential and smaller corrosion current density, which suggested that the corrosion resistance was improved with increasing addition of Sr element. The corrosion resistance of Mg65Zn30Ca4.5Sr0.5 alloy was the highest among the 2mm rod samples, while the corrosion resistance of Mg65Zn30Ca4Sr1 alloy was the best among the 4mm rod samples.