Endoscopic diagnosis and classification of reflux esophagitis were described, which is gradually increasing in number in Japan. It is important to diagnosefor a type, grade, and degree, hearing stage and others (stenosis, Barrett's esophagus etc), when we perform endoscopic examination for reflux esophagitis patients. Iodine staining should be applied as far as possible. Los Angeles system for classification of reflux esophagitis was proposed at the 10th World Congress of Gastroenterology in October 1994. As for LA classification, reflux esophagitis is classified to 4 grade, from A to D, predicated on the grade of mucosal break. For any doctors, this is easy to apply to the classification of reflux esophagitis and the diagnosis of classification will be equal. The Japanese Society of Disease of Esophagus also proposed the new classification of reflux esophagitis, that is JSED '96 Classification. This classification contains grade 0, which indicate no reflux esophagitis and grade 1, which indicate the discoloring type of esophagitis. Another 3 grades are based on the length of esophagitis and also occupation on circumference of esophagus. This will be suitable for the Japanese reflux esophagitis and can be changed to LA classification easily. The International Society of Disease of Esophagus proposed AFP classification which is useful to decide the application to surgical treatment. The detail of these classifications and the important points on the endoscopic diagnosis of reflux esophagitis were mentioned in this paper.