Different application scenarios put forward diverse requirements of mechanical properties for magnesium alloys. In this study, the extruded Mg-Sc-Nd-Zn alloy series with high plasticity and medium strength was developed. The uniformly distributed Mg3Nd (β1) phase, high-density twins, and the activated non-basal dislocation slips contribute to the high plasticity of Mg-Sc-Nd alloy. With the addition of Zn element, the appearance of coarse ScZn phases, which prevents the activation of {10 2} tensile twins, leads to an increase in strength but a simultaneous decrease in the plasticity of the extruded alloys. Adjusting the Zn content in the Mg-Sc-Nd-xZn allows a series of alloys with various strengths and plasticity matching. The results obtained in this work are of great importance for developing a regulatable magnesium alloy series that aims at different application scenarios.