Abstract: Objective To evaluate the therapeutic effect, adverse effect and complications of hypo-fractionated three-dimensional conformal radiotherapy(3DCRT) for patients with initial non-small cell lung cancer (NSCLC). Methods Thirty-nine patients were finally diagnosed by pathohistology and (or) cytology,all the patients who refused to be treated by surgery or couldn t be treated by surgery received hypo-fractionated 3DCRT, the fractionated doses were from 4Gy to 6Gy, five times a week,the total doses were from 60Gy to 76 Gy, the biologically effective doses (BED) were f rom 80. 6 Gy to 100. 4 Gy. The plan targeted volume ( PTV) included the primary tumor and metastatic nodes. 18 cases of them were combined with 2～4 cycles chemotherapy af ter radiotherapy. Results 　The complete response (CR) rate was 66. 7 %(26/ 39), in which the CR rate of whose BED < 90 Gy was 50 % (9/ 18), the CR rate of whose BED ≥90 Gy was 80. 9 % (17/ 21), there was significant difference between the patient s whose BED < 90 Gy and whose BED ≥ 90 Gy ( P < 0. 05) . The overall 1 year, 3 year, 5 year survival rate was 100 %、84. 2 % and 33. 3 %, respectively. The therapeutic effect s were a little less than the radical resections. The radiation esophagitis higher than grade 3 was not found and only one patient was accompanied with grade 4 radiation pneumonitis. Conclusion 　Could hypo2f ractionated 3DCRT replace operation in the t reatment of initial non2small cell lung cancer ? It deserves doing research further.