The LASEREO system (Fujifilm Corporation), a new linked color imaging (LCI) technology using a laser, allows users to easily recognize subtle differences in mucosal color. With LCI images, we can achieve simultaneous expansion and shrinkage of colors and intensify shades of both red and white due to simultaneous irradiations with white light and short-wavelength narrow band light at an appropriate ratio. Thus, LCI visualizes tumors in noticeable colors and with distinctive outlines. With using LCI, total 86% of the cases were visualized with enhanced redness and/or faded colors, and 87% of the cases were visualized with enhanced outlines. LCI improves the capability of detecting gastric cancers by visualizing tumors in noticeable colors such and lavender and orange and changing the color of mucosa surface making cancer lesions to stand out. LCI can be the standard examination for detecting upper gastrointestinal tumors in high-risk patients. I will present some early-stage gastric and esophageal cancer cases detected by LCI observation.