Six　alloys　with　different　compositions　of　Al-0.1%　Sc,　Al-0.3%　Sc,　Al-0.3%　Zr,　Al-0.1%　Sc-0.1%　Zr,　Al-0.3%　Sc-0.1%　Zr　and　Al-0.3%　Sc-0.3%　Zr　were　prepared　by　casting　in　a　wedge　shaped　copper　mould.　The　hardness　test,　microstructure　observation,　and　DSC　thermal　analysis　were　applied　to　fully　investigate　the　solidification　behavior　of　the　wedge　tip　(whose　cooling　rate　is　1000　K/s)　and　the　top　surface　(cooling　rate　100　K/s)　of　each　casting.　The　results　show　that　the　cast　structures　in　the　hypoeutectic　region　of　Al-Sc　alloys　are　slightly　affected　by　cooling　rates　during　the　solidification.　In　the　case　of　hypereutectic　alloy　of　Al-0.3%Sc-0.3%Zr,　the　cast　grains　were　remarkably　refined　under　the　condition　of　a　100　K/s　cooling　rate,　however,　under　a　1000　K/s　cooling　rate　condition,　solute　atoms　contribute　nothing　to　the　grain-refinement,　due　to　the　eutectic　concentration　becomes　higher.　The　hardness　can　be　improved　to　a　greater　degree　by　Se　single　addition,　compared　to　single　Zr　addition,　but　it　can　be　improved　even　greater　when　Sc　added　together　with　Zr.　It　is　sensitive　to　cooling　rate,　the　higher　the　cooling　rate,　the　greater　the　hardness.　By　combining　the　results　of　TEM　examination　and　DSC　analysis,　it　can　be　seen　that　a　supersaturated　Al　solid　solution　forms　during　the　solidification,　and　the　solubility　of　Sc　in　Al　solution　can　be　improved　by　increasing　the　cooling　rate.