Chronic atrophic gastritis type O1 is a type classified by Takemoto Kimura. It is an endoscopic method of describing the extent of gastric atrophy. O1 refers to the gastric mucosal atrophy limit just past the cardia, while the inflammatory infiltration has not reached the fundus and the body of the stomach, which belongs to moderate atrophy. Chronic atrophic gastritis type O1 is relatively mild compared to the severe atrophy of type O2 and O3, and may manifest as abdominal distension, indigestion, vomiting and weight loss. However, gastroscopy alone is not sufficient to determine the severity of the disease, and it is necessary to combine with the pathologic findings of the atrophic areas to make a comprehensive judgment. Chronic atrophic gastritis type O1 should be treated promptly to avoid malignant changes. If it is clear that there is Helicobacter pylori infection patients need to be under the guidance of the doctor on the eradication of Helicobacter pylori treatment, such as triple therapy or quadruple therapy.