Abstract: To understand the characteristics of lymph node metastasis at the thoracic inlet in thoracic esophageal carcinoma ( TEC ), and to investigate the reasonable clearing range of upper mediastinal lymph nodes. Methods: Clinical and pathological data of 150 patients who underwent three-incision radical surgery for TEC in our hospital from November 2004 to June 2010 were analyzed. Results: The incidence of lymph node metastasis among all patients was 60.7% in which the nodal metastasis at the thoracic inlet was 32.7%, and the degree of metastasis was 20.99%. Univariate analysis showed that the TEC at the upper, middle, and inferior segments could metastasize to the lymph nodes of the thoracic inlet; the rates of nodal metastasis at the inlet of thorax of each segments, that is, the upper, middle, and inferior segment, were 57.7%, 28.9%, and 23.5% ( χ2 = 9.02, P = 0.01 ), respectively. There were statistical differences in the lymph-node metastasis at the inlet of thorax among different segments. The lymph-node metastases with different degrees of differentiation, specifically, the well, moderately, and poorly differentiated cells, were 13%, 40.9%, and 43.8%, respectively. Statistically significant differences were observed among the metastatic rates of lymph nodes at the thoracic inlet with different degrees of differentiation ( χ2 = 11.67, P = 0.003 ). There were no statistical differences among the depth of the tumor infiltration, the tumor size, and the rate of lymph node metastasis at the thoracic inlet. Multivariate analysis indicated that the histologic differentiation of the tumors and the diseased regions were the risk factors that affect lymph node metastasis at the thoracic inlet. Conclusion: Lymph node dissection at the thoracic inlet plays an important role in preventing the regional recurrence and metastasis of TEC after surgery.