Influenza is a common respiratory infectious diseases.In recent years,the increasing number of the secondary infection after influenza has been reported,which is related to the changes of microecology in the respiratory tract caused by influenza virus.But there are few researches on the effects of respiratory microbial communities during the period of influenza,especially the differences between the types of TCM syndromes.Study on micro-ecological changes in the respiratory tract of patients with influenza is very important to prevent the secondary infection,which can reduce influenza hospitalization rate and mortality,especially guide the application of traditional Chinese medicine.