An Endoscopic spectrophotometer has been developed and applied for measuring the spectral reflectance from 450 nm to 900 nm of the gastric mucous membranes for 72 patients. Those obtained spectral reflectances are analyzed in detail and the capabilities of automatic diagnosis of stomach disorders such as polyp, erosion and ulcer are discussed. From these analysises, it became clear that the spectral reflectances of the normal and abnormal membranes differ from patient to patient. The chromaticities of the gastric mucous membrane for individual patients were calculated and analyzed. As a result, it was seen that it can be classified normal and abnormal for each patient separately.