Abstract: The assay was aimed to investigation and analysis on mains pathogen in cow mastitis and pathogen sensitivity to antibiotics in dairy farm of Jilin city. We collected aseptically cow mastitis milk samples, and conducted isolation, cultivation and drug sesitivity test. The results was indicated that hemolytic Streptococcus was main pathogenic bacteria cause to cow mastitis in dairy farm. Not only the pathogen had strong drug resistance, but also it could resist many antibiotics. In conclusion, the pathogenic bacteria had strong pathogenicity and drug resistance in dairy farm.

Key words: cow; mastitis; isolation and cultivation; drug sensitivity test