Abstract: Objective: To explore the effect of radiotherapy on preventing the recurrence of lymph node metastasis of esophageal cancer after Ivor-Lewis esophagectomy. Methods:Three hundred and sixty-six pa-tients with middle third squamous cell carcinoma of the esophagus were enrolled in this study. All patients underwent Ivor-Lewis esophagectomy with two-field lymph node dissection in our hospital between June 1999 and June 2004. All statistical analyses were performed with SPSS 13.0 statistical software. Kaplan-Meier method was performed to calculate the relapse rate. Log-rank test was performed to compare the relapse rate. Cox regression analysis was performed to identify independent prognostic factors for postoperative lymph node metastasis. Results: Of the 366 cases, lymph node metastasis was found in 105 patients (28.5%) within 3 years after surgery, occupying 52.2% (105 /201 ) of total recurrence. Of the 181 patients treated with postoperative radiotherapy, lymph node metastasis was found in 37patients. The rate of lymph node metasta-sis was 20.4%, significantly lower than that in patients treated with chemotherapy alone and those without sys-temic adjuvant therapy ( P<0.05). Chemotherapy was administered in 103 cases and lymph node metastasis was found in 33patients. The rate of lymph node metastasis was32.0%, lower than that in patients without systemic adjuvant therapy, but without statistical significance (P=0.17). The results of Cox analysis demon-strated that T stage, lymph node metastasis and postoperative adjuvant radiotherapy were independent prog -nostic factors. Conclusion:Ivor- Lewis esophagectomy for the middle third thoracic esophageal cancer was a safe surgical procedure. Postoperative radiotherapy is helpful for the control of local recurrence. T stage, lymph node metastasis and postoperative adjuvant radiotherapy are independent prognostic factors. Radiotherapy is helpful for preventing the recurrence of lymph node metastasis of esophageal cancer after Ivor-Lew -is esophagectomy.