Abstract: The effects of (1.0, 2.0 and 3.0 wt.%) rare earth Neodymium, Nd addition on microstructure and mechanical properties of as-cast Mg-Ce-Zn-Zr alloy (base alloy) were investigated. The solidification as cast microstructures and phase constitution were characterized by using optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive spectrum (EDS) and X-ray diffraction (XRD). Tensile properties of the investigated alloys were measured by tensile test including yield strength, ultimate tensile strength and elongation. Results indicated that the solidification microstructures of Nd-containing alloys are mainly consists of two phases, α-Mg and (Mg, Zn)12(Ce, Nd) phase. Nd addition led to significant grain refinement and increased volume fraction of (Mg, Zn)12(Ce, Nd) phases. Furthermore, Nd addition significantly decreased the average grain size of as-cast base alloys by approximately 19.68%. Both yield strength and ultimate tensile strength of Nd-containing alloys also increased, whereas significantly detrimental to elongation which decreased by 19.7%.