The　refining　effect　of　Al3Ti1B1RE　master　alloy　on　Al　sheets　used　for　pressure　can　manufacture　and　the　behavior　of　mixed　rare　earths　(RE)　in　master　alloy　were　investigated　with　XRD,　OM,　SEM　and　EDAX.　It　is　found　that　the　refining　effect　of　the　refiner　on　the　material　has　superiority　over　foreign　or　domestic　Al5Ti1B　refiner,　and　the　refiner　still　retains　its　refining　ability　for　6　h　after　adding　it　to　molten　Al,　thus　improving　the　strength　and　plasticity　of　the　material　remarkably.　The　excellent　refining　effect　and　stability　of　ATiBRE　refiner　result　from　that　RE　can　lower　the　surface　energy　of　molten　Al　and　improve　the　wetting　characteristics　of　molten　Al　on　refinement　nuclei　such　as　TiAl3,　TiB2,　etc.,　thus　giving　full　play　to　the　effect　of　heterogeneous　nucleation　and　impeding　the　congregating　tendency　of　TiB2　phase　in　molten　Al.　At　the　same　time,　RE　gathering　in　front　of　solid/liquid　interface　are　also　easy　to　cause　composition　supercooling　in　molten　Al,　thus　impeding　the　growth　of　alpha-Al　grains　and　promoting　alpha-Al　nucleation　on　refinement　nuclei.　In　addition,　RE　also　play　certain　role　in　purification　and　grain　refinement,　or　modification,　especially　their　effect　of　purification　can　improve　the　metallurgical　quality　of　AlTiBRE　master　alloy.