Abstract： Objective To analyze the treatment results of primary nasopharyngeal carcinoma(NPC)treated by four different external beam radiation therapy(EBRT)techniques in Sun Yat-sen University Cancer Center in the beginning of the 21 st century.Methods The data of 1093 hospitalized primary NPC patients treated in Sun Yat-sen University Cancer Center between December 2001 and June 2003 were retrospectively analyzed.The stage distribution(by AJCC/UICC,2002)was 63,439,358 and 233 patients in Stage Ⅰ,Ⅱ,Ⅲ and Ⅳa+Ⅳb.Definitive radiotherapy was given to all patients and the median total dose was 70 Gy.Four different EBRT techniques were used:812 patients with fluoroscopy simulation conventional radiotherapy(CR),155 patients with CT simulation conventional radiotherapy(CT-sim CR),69 patients with three dimensional conformal radiotherapy(3DCRT)and 57 patients with intensity modulated radiotherapv(IMRT). Results The 5-year local failure-free rate(LFFR),nodal failure-free rate(NFFR),and distant metastasis-free rate(DMFR)were 86.8%,95.3%and 83.2%,respectively.The 5-year progressionfree survival(PFS)and overall survival(OS)were 66.9%and 77.9%,respectively.Different EBRT techniques influeneed the OS and the LFFR of patients,the 5-year OS and LFFR of group CR,CT-sim CR,3DCRT and IMRT were 75.9%,83.5%,87.2%,86.6% and 84.5%,96.4%,91.0%,91.7%,respectively(P=0.014 and 0.006).The morbidity and severity of xerostomia and trismus were sigficantly lower in group 3DCRT and IMRT than in group CR and CT-sim CR(P=0.000 and=0.023). Conclusion The CT simulation technique,3DCRT and IMRT can improve the OS,LFFR and life qualitv of patients with primary NPC.