This invention relates to two antigen epitopes and mimotopes of TRAP ( Target of RNA III-activating protein) , a regulatory protein of virulence factor in staphylococcus aureus. The amino acid sequence of the antigen epitopes is NPTHQLFQFSASDT or SYFERYLYPIKE. The amino acid sequence of the mimotopes is XPXHHQHXTGFT or SWFDXXLYPXXX, wherein X represents any one of 21 kinds of natural L-type amino acid residues or D-isomers thereof. The antigen epitopes and mimotopes thereof of the present invention can be used for the preparation of a novel vaccine or medicament for combating against staphylococcus aureus infection.