Objective To analyze the causes of chronic cough. Results Totally 146 patients with chronic cough were diaguosed according to the diagnostic routine based on the guideline on diagnosis and treatment of chronic cough established by Chinese Medical Association, which included medical history, medical examination, X-ray or CT of paranasal sinus or chest, lung function, gastroscope, sputum cytology classification. The final diagnosis was made based on clinical manifestation examination findings and a positive response to therapy. Conclusion The cause of chronic cough was defined in 93.2% of the patients, and multiple causes: Cough variant asthma (n = 45,30.3%), postnasal drip syndrome,PNDs (n = 27, 18.5%), gastroesophageal reflux cough(n = 21,14.4%), post infection cough(n = 16,10.9%), ensinophilic bronchitis(n = 13, 8.9%), drug induced cough(n = 10,6.8%), unidentified cough(n = 10,6.8%). Conclusion Complex etiology of chronic cough,be specific therapeutic effect,and its clear cause is the key to treatment.