The microstructures, mechanical properties and fracture behaviors of Mg-2Zn-0.8Mn -0.5Ca alloy are studied in different conditions, including as-cast and solution treated conditions, to reveal the effect of solution treatment on the microstructures and mechanical properties. The morphologies of the solution treated alloys show that the Ca2Mg6Zn3 phases disperse uniformly within the α-Mg matrix after heated solution at 415 °C for 48 h. The mechanincal properties are investigated in as-cast and solution treated alloys. For the as-cast alloy, the rupture pattern is intergranular fracture because the Ca2Mg6Zn3 phases mainly distribute at the grain boundaries. After solution treatment, the fracture pattern mainly becomes to transgranular fracture. After solution treatment, the ultimate tensile strength, the yield strength and the elongation are improved by 39.4 %, 32 % and 81.3 %, respectively.