Amyloid deposition was investigated in the biopsied specimens obtained from the stomachs of suspected cases of amyloidosis. The subjects were seven cases of suggestive amyloidosis with clinical symptoms of muscle rigidity, masked face, macroglossia and B-J proteinuria. The stomach of an autopsied amyloidosis patient was also investigated. 2. Mucosal tissue was obtained from fundus, corpus and antrum of the stomach using gastrofiberscope, Olympus GFB2. And amyloid in the tissue was detected by H & E Congo red staining and polarization microscopy. Rectal biopsy was also done in the majority of the cases to compare with stomach biopsy. 3. Positive results were obtained with gastric biopsy in all seven cases and five of the 5 cases by rectal biopsy. Thus, gastric and rectal biopsy yielded the same results so far as detection of amyloid deposition was concerned. 4. Biopsy specimens from several sites of the stomach gave similar results in regard to the amyloid deposition. Tissue deposition of amyloid in the stomach wall showed a somewhat high incidence in the walls of intramucosal capillaries and in the walls of blood vessels of lamina muscularies mucosa. Gastroscopic biopsy of the stomach proved to be useful as a routine technique for the definite diagnosis of the disease.