The routine preoperative examination items for esophageal cancer mainly include the following: 1) Examination to confirm the diagnosis of esophageal disease: mainly (1) Gastroscopy and biopsy can directly observe the morphology of the lesion, the degree of obstruction, etc., and accurately locate the lesion, while biopsy can directly characterize the lesion. (2) Upper GI barium meal can show the morphology of the diseased esophagus, indicate the location of the lesion, suggest the local invasion of the lesion, etc., which is important for esophageal surgery; these two examinations are necessary before esophageal cancer surgery. (3) Other tests, such as endoscopic examination of esophageal ultrasound and CT of the chest, have certain significance in determining the invasion and metastasis of esophageal cancer; (4) Tumor markers, such as CEA, CA199, CA125, etc., provide reference for the diagnosis of tumor diseases. (2) For patients with history of heart disease, preoperative cardiac ultrasound should be performed to understand the heart function, and 24-hour long-range electrocardiogram should be performed for elderly patients and patients with arrhythmia. (3) For patients with history of lung disease, preoperative pulmonary function tests and arterial blood gas analysis should be performed to understand the lung function. (1) Ultrasound of abdomen, including liver, bile, spleen, pancreas, kidney, adrenal gland, retroperitoneum, etc. If necessary, enhanced CT scan of abdomen should be performed to assist in the diagnosis of metastasis of related organs; (2) Chest CT scan should be performed to assist in the diagnosis of lung metastasis if there are abnormal nodules in the lung; (3) SPECT bone scan should be performed if the patient has bone pain symptoms or chest or back pain. SPECT bone scan should be performed to understand whether there is bone metastasis, and PET (Positron Emission Tomography) scan is feasible if necessary.