A retrospective study of 44 patients who were involved in combination with chronic sinusitis and bronchiectasis provided better understanding of the etiology in the relationship between upper air ways tract and lower air way tract. The incidence of bronchictasis was found in 5%, 3 out of 60 cases with chronic sinusitis and that of chronic sinusitis in 45%, 44 out of 98 cases with idiopathic bronchiectasis. Both side involvements of the paranasal sinus and the lung were statistically high in sinobronchiectasis compared to chronic sinusitis or bronchiectasis involved alone. The past history of the patients with sinobronchiectasis showed high occurrence of bronchial asthma or allergic rhinitis, habitual angina of the throat, acute otitis media and pneumonia. A chest X. Ray evaluation of 70 patients with chronic sinusitis alone revealed relatively high incidence of abnormal fibro-nodular shadow in the lung compared to 70 patients without chronic sinusitis. It was thought that weakness of air-way tract to infection in the patients with sinobronchiectasis might play some role on break down of sino-bronchial syndrome, a combination disease of chronic sinusitis and chronic bronchitis.