The small cell carcinoma of the lung is a highly malignant tumor and 5 year survival rate is approximately 1 % It has three characteristics-large growth fraction rapid doubling time and abnormal peptide production. It responds well to both radiation therapy and chemotherapy. Form March 1983 to July 1987, 44 patients with histologically confirmed small cell carcinoma of the lung have been reviewed retrospectively. The results were as follow ; 1. There were 36 men and 8 women. the range of age was 31 to 74 years old(average age-57.2 yrs).Of the 44 patients 40 patients had smoking history 33 were smoker and 7 were nonsmoker. 2. In simple chest hilar and mediastinal enlargement were the most common finding secondary findings due to tumor were the next and peripheral pulmonary nodule was the least common finding. 3. Of the 44 patients 20 patients had been taken chest CT scan, Most patients showed hilar and mediastinal enlargement. Additionaly CT scan showed pulmonary nodule bronchial narrowing and atelectasis etc, The upgrade staging after CT scan was 55% 4. CT scan is sensitive to detect the mediastinal lymphadenopathy or pulmonary mass and should be the initial radiographic procedure for staging and follow up study.