Bovine mastitis is a worldwide disease that affects dairy cattle and is characterized by inflammation of mammary gland. Severity of inflammation depends of causative agent and host response to it. Antimicrobial peptides play an important role in innate immune defense mechanisms of mammary gland against mastitis causative microorganisms. By using qPCR on mammary gland tissues: cistern, parenchyma, Füerstenberg’ rosette, streak canal, and inguinal lymph node, with mastitis by Sthapylococcus aureus, we found that β-defensins lingual antimicrobial peptide (LAP) and tracheal antimicrobial peptide (TAP) were mainly expressed in cisternal and parenchymal tissues. The S100A7 protein was highly expressed in streak canal, although some expression was detected in Füerstenberg’s rosette, cistern, inguinal lymph node, but no in parenchymal tissue. Therefore, these peptides could play a key role in the mammary gland with mastitis by S. aureus.