Abstract: Objective : To investigate the prognostic factors for patients with nasopharyngeal carcinoma (NPC) who received radiotherapy (RT) and to provide information about improvement in NPC RT techniques. Methodse : We retrospectively analyzed the data from 840 cases of NPC that received RT from January 1996 to December 2001 in our hospital. The Kaplan-Meier method was used to calculate the control rate of nasopharynx, the tumor-free survival rate and overall survival. Log-rank test was conducted to determine significance. The Cox proportional hazards regression model was used to confirm the significance of prognostic factors. Results : 1) The total control rates of nasopharynx for 3, 5 and 10 years were 70.6%, 56.7% and 36.6%, respectively. The tumor-free survival rates for 3, 5, and 10 years were 66.8%, 51.8% and 32.0%, respectively. The overall survival rates for 3, 5, and 10 years were 73.8%, 58.6% and 39.4%, respectively. 2) Univariate logistic regression analysis showed that gender, age, clinical stage, T stage, N stage, skull base invasion, cranial nerve invasion, nasal cavity invasion, cervical node metastasis, unilateral/bilateral neck node metastasis, cervical node metastasis position, intracavity brachytherapy of nasopharynx, external beam radiotherapy method and chemotherapy were significantly associated with the control rate of nasopharynx, tumor-free survival, and overall survival (P<0.05). The irradiation dose of nasopharynx was significantly associated with the nasopharynx control rate and overall survival (P<0.05). The tumor-free survival of the patients with carotid sheath involvement was low-er than that of the patients without carotid sheath involvement (P<0.05). 3) Multivariate logistic regression analysis showed that gender, age, clinical stage, T stage, unilateral/bilateral cervical node metastasis, and intracavity brachytherapy of nasopharynx were independent influential factors of the control rate of nasopharynx, tumor-free survival and overall survival. 4) The stratified analysis showed that T2 and T3 patients who received adjuvant high dose intracavity brachytherapy of nasopharynx presented with a higher control rate of nasopharynx, tumor-free survival and overall survival (P<0.05). Conclusion : Male NPC patients with advanced clinical stage (especially T stage) and bilateral cervical node metastasis have a poorer prognosis. Adjuvant intracavity brachytherapy of nasopharynx can improve the prognosis of T2 and T3 patients.