In this study, as-cast Mg, ZXM100 (1.07Zn-0.21Ca-0.31Mn) and ZXM120 (1.01Zn-1.63Ca-0.30Mn) alloys were produced by gravity die casting method, and microstructure, phase analysis, corrosion and mechanical properties of the alloys were investigated comparatively in order to develop degradable Mg-based biomaterials with improved properties. It is observed that Ca2Mg6Zn3 phase is expected to be present in ZXM100 (1.07Zn-0.21Ca-0.31Mn) alloy totally dissolved in the alpha-Mg matrix after homogenization heat treatment. However, Mg2Ca phase is expected to be present in ZXM100 (1.07Zn-0.21Ca-0.31Mn) alloy partially dissolved in the alpha-Mg matrix. Results showed that ZXM100 alloy has a much more homogeneous structure, a better performance, higher corrosion resistance and mechanical properties than those of as-cast Mg and ZXM120 alloy. ZXM100 (0.099 mm/year) alloy has a three times slower corrosion rate than ZXM120 (0.294 mm/year) alloy. It is found that the ZXM100 alloy has closer values to the desired corrosion rate and mechanical properties as a biodegradable implant material.