[Objective] In order to study the in vitro antibacterial effects of Chinese herbal medicines on main pathogenic bacteria of dairy cow mastitis. [Method] 10 Chinese herbal medicines such as Honeysuckle were selected to determine the minimum antibacterial concentrations of Staphylococcus aureus,Escherichia coli and Streptococus agalactiae by test tube two-fold dilution method. [Result] The Chinese herbal medicine had different degree of bacteriostatic effect on main pathogenic bacteria. Forsythia had the best antibacterial effect on Staphylococcus aureus,with MIC of 15.63 mg/mL. Radixisatidis,Dandelion and Scutellaria baicalensis had the he best antibacterial effect on Escherichia coli,with MIC of 62.5mg/mL. Lilac had the he best antibacterial effect on Streptococus agalactiae,with MIC of 15.63 mg/mL.[Conclusion] This study provided technical reference for clinical development of Chinese herbal medicine mastitis preparation.