Abstract: Objective To study the expression of Bcl-2 protein in locally advanced non-small cell lung cancer(LANSCLC),and to evaluate its relationship with radiosensitivity and prognosis.Methods We analysed data from 88 patients with inoperable locally advanced non-small cell lung cancer from 2002 to 2006 in our hospital.The expression of Bcl-2 was detected by immunohistochemical method in resected tissue specimens gained by fibre branchoscopy test or CT-guide percutaneous lung puncture biopsy.The patients were divided into chemoradiotherapy squamous cell carcinoma group(CRSG),chemoradiotherapy adenocarcinoma group(CRAG)and radiothe rapy squamous cell carcinoma group(RSG),and then each group were divided into expression of Bcl-2 negative group and positive group,and to evaluate the short-term efficacy of radiation therapy,without recurrence survival time(RFS),overall survival(OS),1,2,3-year survival rate.Results The positive expression rate of CRSG,CRAG and RSG were 20.9%(9/43),30.8%(8/26)and 26.3%(5/19)respectively.The short-term radiation therapy efficacy of Bcl-2 positive expression groups of CRSG and CRAG were lower than that of the negative expression groups,the radiation therapy RFS of Bcl-2 positive groups of CRAG and RSG were lower than that of the negative expression groups,the radiation therapy OS of Bcl-2 positive group of CRAG were lower than that of the negative expression group.Bcl-2 positive and groups of CRSG,CRAG and RSG ′s median survival time respectively were 13,12 and 12 months;while negative groups were 26 months,23.5 months,14 months.The variance of 1,2,3-year survival rates of CRAG were significantly(P=0.0047).Conclusion The data show that the expression of Bcl-2 in LANSCLC as anegative factor of RFS maybe associate with the radiotherapy.The findings might suggest that there were negative correlation between expression of Bcl-2 and the prognosis of LANSCLC.Bcl-2 inhibitors may have great efficacy in the radiotherapy of NSCLC.