Objective:To observe the situation of Yupingfeng San and α-Hemolytic streptococcus to prevent bacteria Staphylococcus aureus invasion,and to adjust micro-ecological balance ment situation in upper respiratory tract.Methods:Flora imbalance in the upper respiratory tract of mice were respectively fed to Yupingfeng or Yupingfeng San plus α-Hemolytic streptococcus by oropharyngeal infusion for 7 days.Then to attack mice by Staphylococcus aureus oropharyngeal infusion for three days.To test flora Density,α-Hemolytic streptococcus quantity,flora diversity in the upper respiratory tract flora of mice at different time points.Results:Taking yupinfeng San can ease flora disturbance in oropharyngeal of mice and play a role against harmful bacterium attacking.Oropharyngeal colonization of Streptococcus can be enhanced this role.Yupinfeng San can adjust the growing of α-Hemolytic streptococcus,to Maintain its position of dominant bacteria and the micro-ecological balance of the upper respiratory tract.Condusions:We could consider using traditional Chinese medicine therapy or probiotics intervention to combat harmful bacterial infections of upper respiratory tract.