We performed a tracheotomy on 363 cases, (during an 11 year period from Jan. 1957 to Dec. 1967) for the purpose of maintenance of airway and other reasons. We did statistic observation on these material and then obtained as follows. 1) Most frequent cause for the operation was acute laryngeal infection in 284 cases (78%), others were laryngeal tumors in 45 cases (12%), foreign body in the larynx, trachea and bronchus in 15 cases (4%), and other miscellaneous causes in 19 cases (5%). 2) Tracheotomy was performed most frequently in 1-5 year age group showing 223 cases (61%), and 6-10 year age group 83 cases (23%) next in order. 3) Sex ratio between male and female was about 2 : 1 showing 245 cases (67%) in male and 118 cases (33%) in female. 4) The operation was most frequently performed in 1966 (55 cases (15%)). The months of the highest frequency were Dec. and Nov. 5) The majority of the patient (134 cases (41%)) had the 1st examination on the 3-4th day after onset of disease, next in order of frequency was examination on the 1-2nd day from onset. 6) Emergency tracheotomy was done in 24 cases (7%). The operation was done in 256 cases (71%) under endoscopy. 7) The tracheal tube was able to be removed in 101 cases (28%) on the 5th post-operative day and in 67 cases (18%) on the 6th post-operative day. 8) The most common complication was subcutaneous emphysema which occurred in 28 cases (8%) among 54 cases (15%). The other complications were pneumothorax, mediastinal emphysema and difficulty in decannulation.