Objective To investigate the long-term survival of esophageal squamous cell carcinoma (ESCC) patients of different ages after three-dimensional conformal radiotherapy (3 DCRT).Methods From July 2003 to September 2008,769 patients with stage Ⅰ-Ⅲ ESCC were eligible for the analysis.All patients were treated with 3DCRT.The prescribed dose was 50-70 Gy (median,60 Gy),1.8-2.0 Gy per fraction,5 fractions per week.The Kaplan-Meier method was used to calculate overall survival (OS) and local control (LC) rates; the log-rank test was used for survival difference analysis and univariate prognostic analysis;the Cox regression model was used for multivariate prognostic analysis.Results The follow-up rate was 98.3％.For all patients,the 1-,3-,and 5-year LC rates were 76.3％,52.8％,and 48.5％,respectively,and the 1-,3-,and 5-year OS rates were 70.1％,36.2％,and 23.0％,respectively.The 1-,3-,and 5-year OS rates were 71.2％,38.8％,and 24.9％,respectively,for patients aged 45-74 years,versus 69.6％,26.6％,and 15.4％ for patients aged 75-89 years (P =0.008).Multivariate prognostic analysis showed that age was also a prognostic factor in ESCC patients after 3DCRT.A total of 620 patients died.Patients aged 45-74 years had a significantly higher proportion of individuals that died of distant metastasis (23.9％ vs.14.2％,P =0.009),while patients aged 75-89 years had a significantly higher proportion of individuals that died of non-cancer diseases (14.1％ vs.4.9％,P=0.000).Conclusions Survival varies between ESCC patients of different ages after 3DCRT.The survival of elderly ESCC patients is poor,and the relatively high mortality from non-cancer diseases may be an important reason for poor survival.