Staphylococcus aureus [1 mL 10 6 cfu (colony forming unit)/mL] suspension was infused into one side of udder chamber of the healthy lactating milky goats. Mastitis model was identified and determined by such indices as clinical symptoms, body temperature, somatic cell count in milk, electronic mastitis detector, pathogen isolation and cultivation, and histopathological changes. The results showed that acute mastitis model can be duplicated by inoculating the above amount of bacteria in one side of udder chamber of lactating goats.