Abstract: Objective : A prospective randomized trial was performed to evaluate the efficacy of concurrent chemoradiotherapy and adjuvant chemotherapy in patients with locoregionally advanced nasopharyngeal carcinoma(NPC) in endemic regions of China. Methods : Between July 2002 and September 2005, 316 eligible patientsthat had non-keratinizing or undifferentiated NPC and were classified as stage III-IVB by the AJCC 5th Editionwere enrolled in the study. The patients were treated with radiotherapy alone (RT) or concurrent chemoradiotherapy plus adjuvant chemotherapy (CRT). All patients were treated by definitive-intent radiation therapy. TheCRT patients received concurrent Cisplatin (40 mg/m² on day 1) weekly during RT, followed by Cisplatin (80mg/m² on day 1) and Fluorouracil (800 mg/m² on days 1 to 5) every 4 weeks for 3 cycles after completion ofRT. All patients were assessed by intent-to-treat analysis. The overall survival (OS) rates, failure-free survival(FFS) rates, distant failure-free survival (D-FFS) rates, and locoregional failure-free survival (LR-FFS) rateswere compared. The toxicity of the regimen and the patient reponse to it were evaluated. Results : The twogroups were well balanced in the distribution of all prognostic factors and RT parameters, such as sex, age,performance status, staging method and clinical stage. The CRT group experienced significantly more acutetoxicities (62.6% vs. 32.3%, P=0.000). There were 107 patients (68.4%) who completed all 7 cycles of concurrent chemotherapy, 84.2% of which had 6 cycles or more while 91% completed 5 cycles or more. Ninety-sev-en patients (61.4%) completed all 3 cycles of adjuvant chemotherapy. The 2-year OS rate was 89.8% for theCRT group, and 79.7% for the RT group (P=0.003). The FFS rate was 84.6% for the CRT group, and 72.5%for the RT group (P=0.001). The D-FFS rate was 86.5% for the CRT group, and 78.7% for the RT group (P=0.024), while the LR-FFS rate for the CRT group was 98.0%, compared with 91.9% for the RT group (P=0.007). Conclusion : In patients with locoregionally advanced NPC in endemic regions of China, concurrentchemoradiotherapy plus adjuvant chemotherapy can improve the OS rate, FFS rate, D-FFS rate and LR-FFSrate. Further study is needed to confirm this effect.