Double extrusion with a large plastic deformation was conducted to fabricate Mg-Nd-Zn-Zr (JDBM) micro-tubes (3.5 mm in outer diameter and 0.25 mm in thickness) with high plasticity for biodegradable vascular stents application. After double extrusion, the grain size was greatly decreased to one seventh of the original size and the basal texture intensity was enhanced slightly. The elongation increases from about 23% for the as-extruded JDBM alloy bar to about 48.8% for the as-extruded micro-tubes, which is a 112% increase by double extrusion. The high elongation is attributed to the enhanced activation of non-basal slips contributed by the significant grain refinement.