Symptoms of heartburn and regurgitation are the most important for diagnosis of gastroesophageal reflux disease (GERD) in the clinical field. Endoscopic examination is also widely used modality for Los Angeles classification of GERD according to endoscopic severity of esophageal mucosal breaks. However, about half of GERD patients reveal no abnormality under conventional endoscopy. These endoscopic negative GERD is called as non-erosive reflux disease (NERD). There is the possibility to underestimate a minute mucosal change of GERD by conventional endoscopy that has the limitation of visual ability. Magnifying endoscopic examination is able to get clear visualization of intrapapillary capillary loops(IPCL), which are usually shown as dot-like structures in esophageal mucosa by a conventional endoscopy. The changing of IPCLs is associated with inflammation and neoplasia of esophagus. Minute change of IPCLs such as a dilation and elongation with regular intervals were reported to be suggestive of inflammatory change in esophagus. Magnifying endoscopic observation of IPCLs is useful for diagnosis of NERD which cannot be visualized by conventional endoscopy.