The work is to inquire clinical characteristic, diagnosis and treatment of radiation esophageal disease induced by radiation therapy for cancers in the thorax. Radiation esophageal disease is divided into acute radiation esophagitis and chronic radiation esophagitis. Acute radiation esophagitis is seen most often in the clinic and its main clinical symptoms are disphagia, odynophagia and substernal chest pain. Acute esophageal effect was observed in 5 of 28 patients (18%) of lung cancer during or after radiotherapy, there was no acute grade 4 or 5 esophageal effect. Less than or equal to grade 3 chronic effects were observed in 2 of 28 patients (5%), there was no chronic grade 4 or 5 esophageal effect. Acute radiation esophagitis usually happens in two weeks after the beginning of treatment, total dose is about 16—20Gy. Chronic radiation esophagitis usually appears in 90 days after the beginning of treatment. Diagnosis should include history of exposure to radiation, which dose exceed the dose threshold and typical clinical characteristics, but the dose threshold is only the reference because of variance of radiotherapy and the difference of individual sensitivity. Endoscopic finding of esophagus is the main way to diagnosis. The conservative measure is used for acute esophagiteal effect, and dilatation is required for chronic esophagiteal effect. The analysis of clinical characteristic, type and diagnostic basis can provide the reference for drawing up diagnostic standard.