Nasopharyngeal angiofibroma is un-common, non-metastasizing, benign tumor, which occurs mainly in the nasopharynx of adolescent males, but it is malignant by location, because of its tendency to erode surrounding vital structures, bleeding tendency in surgical procedure and recur if not completely removed. It is highly vascular and frequent epistaxis and nasal obstruction are prominent, symptoms. Surgical excision is popular treatment method and followed by irradiation, hormone therapy. The author studied the clinical and histopathological analysis of nasopharyngeal angiofibroma which were comfirmed by biopsy during 1961~1975 in E.N.T. dept. of National Medical Center. Following results were obtained ; 1) The incidence was 24 in 43164 out-patients seen at E.N.T. clinic of National Medical Center since 1961 year. Average incidence; 1968, 6 : 1. This incidence is very high than the reported cases of foreigner. 2) Sex : 22 of casees were males and only 2 were females. The male to female ratio was 11 : 1. 3) The age distribution was 8 to 27 year old. The mean age was 15.1 year old. 4) The most frequent symptoms of cases were epistaxis and nasal obstruction. 5) The sites of all nasopharyngeal angiofibroma were nasopharynx. 6) The duration of onset varied from 1 month to 5 years and averaging 17.7 months. 7) X-ray : PNS and skull series were the hazzy densities of maxillary sinuses (12 cases), the destruction of skull base (3 cases). Carotid angiography done in one case. 8) Treatments were surgical (22 cases), irradiation (4 cases) and hormone therapy (4 cases). 9) Blood loss during operation was averaged 4.2 pints. (2120ml) of blood per patient. a) With lig. of E.C.A. ; average 2,214ml (7 cases). b) Without lig. of E.C.A. ; average 2010ml (15 cases). 10) The recurrence rate was averaging 25% (6 cases).