Eosinophil extracellular traps (EETs), an important pathway of eosinophil to exert its effects, are composed of DNA fibers, histone and eosinophil granule proteins. Recently, many researches have shown that EETs play an important role in the genesis and development of respiratory diseases including asthma, allergic bronchopulmonary aspergillosis and chronic obstructive pulmonary disease. EETs can directly damage airway epithelial cells, promote airway inflammation and airway hypersecretion, increase the stickiness of secretions and induce the generation of autoantibody, helping eosinophils and their products participate in a cascade of events leading to inflammation and disease. Researches on EETs can also be helpful in investigating new targets for the treatment of chronic airway diseases.