CONCLUSIONS Autophagy was involved in the radiation treatment of CNE-2 cells, and blocked autophagy enhances the radiosensitivity of nasopharyngeal carcinoma cell line CNE-2 in vitro. OBJECTIVE To determine whether autophagy induced by radiation therapy contributes to tumor cell death or represents a mechanism of resistance to therapy-mediated cell death. METHODS Autophagy in the CNE-2 nasopharyngeal carcinoma cells after radiation treatment was determined by quantitative GFP-LC3 analysis, electron microscopy, and autophagy-related molecules analysis by Western blotting. The contribution of autophagy to the cell viability was determined by MTT assay and clonogenic assay. RESULTS Autophagy was involved in CNE-2 cells post radiation treatment, and autophagy could ameliorate the cell viability post radiation. On the other hand, inhibition of autophagy could reduce cell viability and decrease the cell survival.