The present invention relates to a kind of polypeptide, it includes the Queensland nut albumen selected from the group comprising following protein:PH 6.3 to 8.7 in 2D SDS PAGE 53 to 67kDa protein of electrophoresis and pH 6.5 to 7.9 in 2D SDS PAGE electrophoresis 20 to 25kDa protein or its antigenic variant, preferably in the electrophoresis of pH 6.3 to 8.7 53 to 67kDa protein or its antigenic variant.