Objective To summarize the long term outcomes and prognostic factors of nasopharyngeal carcinoma (NPC) treated by intensity-modulated radiotherapy.MethodsFrom Nov 2001to Dec 2009,totally 416 newly diagnosed NPC patients was treated in our hospital.The prescribed dose was 70-78 Gy to the gross tumor volume and 70 Gy to the positive neck nodes,60 Gy to the clinical target volume,and 50-56 Gy to the clinically negative neck.Among 333 stage Ⅲ/Ⅳ patients according to the 2010 UICC staging system,187 received concurrent chemoradiotherapy with a regimen of weekly cisplatin 30mg/m2.Local control rate (LC),overall survival (OS),disease-hree survival (DFS) and distant metastasis-free survival (DMFS) were estimated using the Kaplan-Meier method.ResultsThe follow up rate is 98.0％.158 patients was followed up more than 5 years.The 5 years LC,OS,DFS and DMFS of whole group were 87.7％,82.1％,71.8％ and 84.5％.Sex,Age,T stage and N stage were independent prognostic factors for OS (x2=4.59,11.20,19.40,18.00,P=0.03,0.00,0.00,0.00),T and N stage were independent prognostic factors for DFS (x2=33.50,21.20,P=0.00,0.00) and DMFS (x2=11.90,14.60,P=0.01,0.01).The 5 years LC,OS,DFS and DMFS for local-regional advanced disease with or without concurrent chemotherapy was 82.2％ and 90.7％ (x2=1.72,P=0.19),70.2％ and 83.4％ (x2=1.42,P=0.23),62.8％ and 73.2％ (x2=2.83,P=0.09),78.0％ and 83.2％ (x2=0.37,P=0.55)respectively.Conclusions The long term outcomes of nasopharyngeal carcinoma treated by intensitymodulated radiotherapy was encouraged.The role of concurrent chemoradiotherapy for locally advanced nasopharyngeal carcinoma treated by intensity-modulated radiotherapy needs further investigated.