A　newly　developed　severe　plastic　deformation　(SPD)　technique,　i.e.　repetitive　upsetting　(RU),　is　employed　to　improve　the　strength　and　ductility　of　a　Mg-Gd-Y-Zr　alloy.　During　the　RU　processing,　dynamic　recrystallization　occurs　in　the　Mg　alloy,　which　leads　to　a　significant　grain　refinement　from　11.2　mu　m　to　2.8　mu　m.　The　yield　strength　(YS),　ultimate　tensile　strength　(UTS)　and　elongation　increase　simultaneously　with　increasing　RU　passes.　The　microstructural　evolution　is　affected　by　processing　temperatures.　Dynamic　recrystallization　prevails　at　low　temperatures,　while　dynamic　recovery　is　the　main　effect　factor　at　high　temperatures.　Texture　characteristics　gradually　become　random　during　multiple　passes　of　RU　processing,　which　reduces　the　tension-compression　asymmetry　of　the　Mg-Gd-Y-Zr　alloy.　(C)　2018　Published　by　Elsevier　Ltd　on　behalf　of　The　editorial　office　of　Journal　of　Materials　Science　&　Technology.