The effects of Nd addition on the microstructure and mechanical properties of Mg–6Zn–1Mn–4Sn alloy have been investigated. The results show that α-Mg, α-Mn, Mg7Zn3, Mg2Sn and MgSnNd phases are found in the as-cast Nd-containing alloys. The MgSnNd phase is a high temperature phase which can enhance the age hardening response of the heat-treated alloys. The ZMT614–1.5Nd alloy under the extruded and aged states exhibits higher strength. This is mainly attributed to the fine grains after extruding and high number density of rod-shaped β1′ precipitates in the α-Mg matrix after aging, respectively.