The　effects　of　combinative　Ca　and　rare　earth　(Samarium,　Sm　and　Lanthanum,　La)　additions　on　the　microstructures,　electrochemical　properties　and　discharge　performance　of　the　as-extruded　Mg-9%Al-1%Zn　(wt.%)　anodes　for　magnesium-air　batteries　are　systematically　investigated.　The　combinative　addition　of　Ca,　Sm　and　La　can　bring　additional　Al2Ca　and　Al-2(Sm,La,Ca)　compound　phase　and　reduce　the　grain　size　from　17.2　+/-　1.9　mu　m　to　11.7　+/-　0.9　mu　m.　The　beta-Mg17Al12　phase　gets　refined　and　dispersed　with　the　Al2Ca　phase　in　the　matrx.　The　modified　Mg-9%Al-1%Zn　anodes　have　more　positive　corrosion　potential　and　better　corrosion　resistance　than　the　original.　The　addition　of　Sm　and　La　strongly　increases　the　desorption　resistance　of　surface　product.　Mg-9%Al-1%Zn　with　Ca,　Sm　and　La　anode　exhibits　stable　discharge　voltage　and　good　discharge　performance.　It　has　high　discharge　capacity　and　anodic　efficiency　of　1381　mA　h.g(-1)　and　61.9%,　respectively,　at　40　mA.cm(-2).　The　prior　corrosion　of　grain　boundaries　makes　bulk　of　alpha-Mg　grains　peel　away　along　the　grain　boundaries,　significantly　reducing　the　anodic　efficiency.　The　disperse　particle　phase　around　grain　boundaries　can　serve　as　strong　barriers　so　as　to　achieve　uniform　dissolution.