The Mg-based metallic glass developed in thisstudy provides an alternative for Mg alloys for being usedin daily life. In this study, the corrosion behaviors of meltspunMgZnCa ribbons with and without heat treatmentwere investigated in artificial sweat. Surface morphologyanalysis showed that amorphous ribbon was more sensitiveto suffer from pitting corrosion. Electrochemical testingand measurement of metal ion concentrations indicate thatribbons in amorphous structure were nobler with smallercorrosion current and possessed much slower dissolutionrate of metal ions. A Zn-rich passivation layer is detectedon the surface of amorphous ribbon, indicating that Zn ismore effective in amorphous ribbon to protect the inneractive metal.