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Effect of calcium content on corrosion rate of AZ61-1.2Y magnesium alloys in 0.5% and 3.5% NaCl solution was studied by the static mass-loss tests. The microstructures of the alloys were observed by optical microscope and the morphologies of corrosion surface were analyzed with scanning electron microscopy. The results indicate that with the addition of 1wt% calcium, the grain size of the AZ61-1.2Y alloys is obviously refined, and the microstructure and component is more homogeneous. But when the addition of calcium is more than 1wt%, the precipitates of the alloys increase and they cause the phenomenon of coarsening and segregation. Furthermore, in 0.5% and 3.5% NaCl solution, the corrosion rates of the alloys decrease firstly and then increase with the increase of calcium content. With the addition of 1wt% calcium, the corrosion rate of the alloys is lowest, and the corrosion resistance is improved remarkably.