Abstract: Objective:To analyze the survival results of the patients with non-small cell lung cancer (NSCLC) treated by radiotherapy alone and the clinical factors affecting the survival results. Methods: Three hundred and eighten patients with NSCLC at the periodfrom January, 1990 to December,1997 were included in this study (stag I, 12 cases; stageII, 71 ctage, IIIA, 158 cases; stage IIIB, 77 cases). All patients were confirmed by pathology and they were treated by cabalt-60 conventionally fractionated, with weekly dose 10一12.SGy. In 49 cases of patients, the treatment planning system was used at the period from the beginning to the semis of radiotherapy, and the primary lesion and medi- astinum were included in the full course of radiotherapy. The irradiation dose on mediastinum was more than 57Gy. For the rest of patients, the mediastinal dose was 40Gy. The survival rate was analyzed by determination of Kaplan-Meier and Log-rank. Results: The median survival for whole group was 10 months. The 1, 3 and 5-year survival rate were 43%, 15% and 9%, respectively. The earlier the clinical stage, the better the prognosis (P=0.0001). The survival rate of the patients with complete remission at the end of radiotherapy was better that of the patients with residual tumor (P=0.0001). The survival of the patients with weekly dose larger than lOGy was better compared to other dose groups (P=0.0461). There was no relationship among the survival rate, the dose and the mediastinal dose. Conclusion: The results show the survival rate of the patient with NSCLC treated by radiotherapy alone is related to the clinical stage, instant response and weekly dose, but not to the total dose and the mediastinal dose.