Objective To observe the pathological changes of esophageal carcinoma after preoperative radiotherapy. Methods A total of 28 thoracic esophageal carcinoma patients treated with surgery following preoperative radiotherapy of 40 Gy (S+R group), and other 28 patients treated with surgery alone (S group) were studied. The pathological changes of the resected samples of these patients were analyzed and compared. In all of the cases, the tumor regression rate, infiltration depth of tumor cells, involvement rate of blood vessels and lymphatic vessels, and metastasis rate of lymph nodes and residual lesions were studied. Results The tumor regression rate in S+R group was significantly higher than that in S group, but the infiltration depth of tumor cells and involvement rate of blood vessels and lymphatic vessels in S+R group were significantly lower than those in S group. The stromal reaction in S+R group was stronger than that in S group. There was no significant difference in metastasis positive rate of lymph nodes and residual lesions between the two groups. Conclusion Preoperative radiotherapy has obvious effect on the treatment of esophageal carcinoma from the view of pathological changes. However, further studies should be conducted on whether the pathological changes mean the improvement of survival rate or not.