Abstract: Objective A retrospective analysis was carried out to investigate the factors of prognostic and recurrence in stageⅢ non-small cell lung cancer.Methods From January 1,1999 to December 31,2004,175 cases with stageⅢ NSCLC received definitive radiotherapy and eligible for the analysis.Establishing 1 year,3-year and 5-year survival rate as endpoints to research the prognosis of NSCLC.Results The investigation was finished at November 9,2009,with a follow-up rate of 95%,those still alive or lost calculated by censoring.The whole group median survival time was 20 months,1,3 and 5 year survival rates were 43%,15% and 3% respectively.Univariate analysis identified 6 significant prognostic clinical factors including T stage,clinical stage,Chemo radiotherapy,radiotherapy interruption,short-term response,acute radiotherapy pneumonia.Cox regression showed that clinical stage,acute radiotherapy pneumonia,short-term response were the independent prognostic factor of patients with stage Ⅲ NSCLC.There is no independent factor associated with local recurrence,clinical stage was an independent factor of distant metastasis.Conclusion The preliminary study results show that the clinical stage of primary tumor,acute radiotherapy pneumonia,short-term response have a significant effect on the survival rate for patients with Ⅲ NSCLC,which provides a reference for the clinical treatment。