The　magnesium　alloy　has　a　unique　advantage　in　3C　fields　due　to　its　high　specific　strength　and　excellent　electromagnetic　shielding　characteristic.　However,　it　is　difficult　to　deform　homogeneously　because　of　hexagonal　close-packed　structure.　In　the　present　work,　the　microstructure,　mechanical　properties　and　stretch　formability　of　magnesium　alloy　sheets　with　different　alloying　elements　were　investigated.　It　was　indicated　that　a　trace　addition　of　Zn　or/and　Er　made　a　key　role　in　modifying　texture,　activating　shear　bands　formation　and　precipitating　nanoscale　second　phases,　respectively,　which　resulted　in　an　obvious　improvement　in　both　stretch　formability　and　mechanical　properties.　The　results　suggested　that　the　Mg-0.5Zn-0.5Er　alloy　sheet　exhibited　higher　tensile　strength　along　the　rolling　direction,　i.e.,　yield　strength　of　180　MPa　and　ultimate　tensile　strength　of　201　MPa,　accompanying　with　superior　Erichsen　value　of　7.0　mm　at　room　temperature.　The　good　performances　of　the　sheet　were　ascribed　to　weakening　basal　texture　intensity,　formation　of　shear　bands　and　precipitation　of　nanoscale　W-phase　(Mg3Zn3Er2).　Graphic　abstract　The　microstructure,　mechanical　properties　and　stretch　formability　of　magnesium　alloy　sheets　with　different　alloying　elements　were　investigated　in　the　present　investigation.　It　was　indicated　that　a　trace　addition　of　Zn　or/and　Er　made　a　key　role　in　modifying　texture　(Fig.　1),　activating　shear　bands　formation　and　precipitating　nanoscale　secondary　phases　(Fig.　2),　respectively,　which　resulted　in　an　obvious　improvement　in　both　stretch　formability　and　mechanical　properties　(Fig.　3).