Objective To analyze primary diseases and risk factors of chronic cough in children,and develop clinical thinking for the doctor,looking for the orderly diagnosis method.Methods The clinical data of 123 children with chronic cough(medical history,physical examination,routine chest X-ray,PPD test,mycoplasma,Chlamydia antibody,antibody of respiratory syncytial virus,adenovirus IgM determination of IgM determination,Coxsackie virus IgM determination,when necessary,be lung CT,CT of paranasal sinuses,gastrointestinal barium meal,bronchiectasis agent diagnostic treatment and surgery consultation) were retrospectively analyzed.The cause of chronic cough in children with primary disease and related factors were analyzed.Results 123 cases of chronic cough in children's primary diseases were asthma-related cough in 57 cases (46.3 %),upper airway cough syndrome (rhinitis,allergic rhinitis,sinusitis) in 41 cases (33.3 %),chronic pharyngitis and tonsillitis,bronchitis in 27 cases (22.0%) ; the main etiology for Mycoplasma Chlamydia(48.8%,60 cases adenovirus),19 cases(15.4%),12 cases of respiratory syncytial virus (9.8%).Conclusion The main primary disease cough,asthma associated upper airway cough syndrome,chronic pharyngitis and tonsillitis,bronchitis,chronic cough in children,the main pathogen Chlamydia,Mycoplasma-for adenovirus,respiratory syncytial virus infection,diagnosis should be based on detailed,comprehensive medical history and physical examination,from simple to complex,according to from low to high,from conventional to special,from noninvasive to invasive principles are examined.