Abstract: Objective To investigate the efficacy and side effects of radiotherapy combined with S-1 for elder patients with esophageal cancer. Methods Sixty elder patients with esophageal cancer were randomly divided into control group and experimental group with thirty cases in each group. Intensity-modulated radiotherapy was applied in the two groups with a total dose of DT 56-64Gy／28-32f. Patients in the experimental group received S-1 chemotherapy concurrent with the radiotherapy on the first day. S-1 was orally given 60mg／m2 daily after meals from d1 to d14 with 21days as a cycle for 2 cycles. Results The efficacy of the 60 patients could be evaluated. In experimental group，CR was in 15 cases，PR in 10 cases，SD in 4 cases and PD in 1 case，and the effective rate was 83.3％. While those of control group were 10，8，8 and 4 cases, and the effective rate was 60.0％. The effective rates of the two groups had statistic significance（P=0.045）.The 1-，2-year survival rates of experimental group were 76.7％ and 56.7％, and those of control group were 53.3％ and 30.0％（P=0.049）.The major adverse effects in the two groups were myelosuppression，digestive tract reaction，radiation esophagitis and radiation pneumonitis，mainly in grade 1-2. The adverse effects between the two groups showed no difference（P＞0.05）. Conclusion Radiotherapy combined with S-1 for elder patients with esophageal cancer is a feasible regimen with tolerable adverse effects and convenient administration，worth clinical application.