We reviewed the histopathological features for the diagnosis of reflux esophagitis and gastroesophageal reflux disease(GERD) including carcinogenesis of the esophagus. Histologically, the presence of capillary dilatation, elongation of papillary, hyperplasia of basal layer, inflammatory cells-infiltration, balloon cells in the epithelium, and ulceration were evaluated in GERD cases. Although, histopathological changes were not clear in endoscopic-negative GERD cases, immunohistochemical examination with cell cycle protein(PCNA, p21, and p27) revealed the same abnormalities with GERD cases. In Japan, the majority cases of GERD are evaluated in grade according to Los Angeles system, therefore the prevalence of Barrett's esophagus and cancer is very low. We hypothesize that esophageal squamous cell carcinoma arising from GERD different from Barrett's cancer sequence, and clinicopathological long-term follow up will be required to assess the carcinogenesis including gene analysis.