The Mg-13Zn-xCa-0.5Nd(x=3,4,5,6) alloys containing high-calcium have been prepared under the pretension of a mix gas atmosphere of Ar .The alloys composite were characterized by a variety of techniques: x-ray diffraction, optical metallurgical microscope, scanning electron microscope and mechanical property test. The performance of high Ca on microstructure and mechanical properties of alloy were investigated. The alloy was mainly composed of α-Mg matrix、α-Mg+Mg6Zn3Ca2 eutectic phase and a few amounts of secondary phase(Mg2Ca+Mg6Zn3Ca2)in as-cast state. The grain is extremely refined with the increase of Ca addition. After the solution treatment at 390 oC for 8 h and subsequent aging at 240 oC, the alloy exhibits greatly mechanical properties.The optimum mechanical property of the alloy is obtained by 4% Ca addition after T6 heat treatment. The ultimate tensile strength, yield strength and elongation of the alloy at peak-aged state are 108 MPa, 175 MPa and 6.10% at room temperature respectively. The good mechanical properties are mainly attributed to fine grain strengthening and second phase strengthenin.