Primary small cell (undifferentiated) esophageal carcinoma is a rare tumor of the esophagus, the incidence of which is rarely reported in China as more than 1% of esophageal malignancies. Its histogenesis is now recognized to be derived from silver cell. Small cell carcinoma of the esophagus occurs in the lower and middle segments of the esophagus and is rare in the upper segment. The tumor mainly presents as a prominent growth into the lumen. Most of them are polypoid or mycosis fungoides. The symptoms are the same as those of other types of esophageal cancer, but complete obstruction to the point of dripping is rare. barium X-ray examination can clarify the location, shape and size of the tumor. CT of chest and abdomen can help to decide whether to operate or not. Esophagoscopy can obtain more cancerous tissues, and most of them can be diagnosed clearly. Small cell carcinoma of esophagus tends to disseminate systemically, and most of them have hematogenous metastasis when first diagnosed. 5-year survival rate is low and prognosis is poor, and few of them are cured by surgery alone, and most of them die within 1 year after surgery, and more than half of them die within 6 months after surgery. At the same time, small cell carcinoma is more sensitive to chemotherapy and radiotherapy, so in addition to early surgery, the effect of preoperative and postoperative chemotherapy and radiotherapy is more ideal. For primary small cell carcinoma of esophagus, if the diagnosis can be confirmed before surgery, except for those who can be operated immediately at early stage, it is appropriate to start with chemotherapy and then surgery or radiotherapy according to the situation, which is believed to have better effect. Comprehensive treatment of small cell esophageal cancer is better than surgery alone.