The microstructure and tensile properties at room temperature of as-extruded Mg94.5Zn4Y1Er0.5 alloy sheet were studied. The results show that the alloy is mainly composed of equiaxial-liked α-(Mg) grains and W phase containing lots of rare earth elements (F.C.C. structure, a=0.707nm). The elongation and tensile strength of the alloy sheet in hot extruded and transverse direction are 25.5 %, 29.9 % and 247 MPa, 240 MPa, respectively. The above results manifest that the W phase stimulate the DRX during hot extrusion, reduce the preference of basal texture of magnesium alloy, markedly improve the plastically shaping capability at room temperature.