1. Patients with high-risk factors for esophageal squamous cell carcinoma who meet any of follows： Long term living in the high incidence area of esophageal squamous cell carcinoma ； First degree relatives have a history of esophageal squamous cell carcinoma ； Previous history of esophageal lesions （ esophageal squamous neoplasia ）； The patients having a history of cancer； A long history of smoking ； A long history of drinking ； Having bad eating habits such as eating fast, hot diet, high salt diet, eating pickles.