In order to further explore the infection mechanism of IL-17A in the pathogenesis and development of bacterial mastitis in dairy cows, in this study, a mastitis model was constructed based on CMECs induced by LPS and the effect of IL-17A on the generation of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and chemokine (IL-8) was investigated. Here, IL17A is linked to mastitis.