The microstructure and mechanical response of as-cast and extruded Mg-2Zn-1Mn-xY alloys (Y content of 0, 0.8 and 2.2 wt.%) have been investigated by optical microscope (OM), scanning electron microscope (SEM) with X-ray energy dispersive spectrometer (EDS), and X-ray diffractometer (XRD). The experiment results reveal that the addition of Y not only decrease the grain sizes of both as-cast and extruded alloys, but also effectively reduce the basal texture intensity of extruded alloys. These are two key reasons for the improvement of the strength and ductility of Mg-2Zn-1Mn-xY alloys, simultaneously. The optimized Mg-2Zn-1Mn-xY alloys after extrusion exhibits an attractive mechanical performance. Compared with the matrix material Mg-2Zn-1Mn, its yield strength increases from 164 MPa to 204 MPa, the ultimate tensile strength increases from 237 MPa to 298 MPa and the elongation increases from 12% to 18%.