From April 1986 to Dec. 1988, fifty one patients with carcinoma of lung were treated by radiation therapy in Department of Therapeutic Radiology, Yeungnam University Hospial. Of the 51 patients, 31(61%) were squamous cell ca, 8(15.7%) were small cell ca, and remained 4(7.9%) were other cell types. Total radiation dose was average 64 Gy (60~75 Gy) for group A and 45 Gy (40~59 Gy) for group B. The mass regression and the response of airway obstruction to radiation therapy was established on the basis of follow up chest X-ray. The mass regression above 50% of total volume was noted in 23 patients (74.2%) among 31 patients and the difference between two groups was not seen. In squamous cell ca, however, the mass regression rate(above 50% of total volume) was 83.3%(10/12) in group A compared to 50%(3/6) in group B(p<0.05). The alleviation of airway obstruction was noted as follows. In group A, CR 42.9%, PR 35.7%, no response 21.4% and in group B, CR 55.6%, PR 33.3%, no response 11.1%. But, in squamous cell ca, responsiveness is higher than group B. The study indicates that the importance of higher radiation dose in the management of primary tumor mass and airway obstruction caused by lung cancer especially squamous cell ca. So, meticulous treatment plaining and multimodality combination therapy without increasing side effect or complication is recommended in management of inoperable bronchogenic carcinoma.