Type A gastritis and type B gastritis belong to atrophic gastritis. The sites of the two types of gastritis are different; type A gastritis is mostly located in the gastric body and type B gastritis is mostly located in the gastric sinus, type A gastritis is mostly diffusely distributed and type B gastritis is distributed in multiple lesions. Clinically, type A gastritis is known as autoimmune gastritis with reduced or lack of secretion of gastric acid and internal factors and predisposition to pernicious anemia, while type B gastritis is more common, most commonly chronic superficial gastritis caused by Helicobacter pylori infection. Mucosal atrophy changes are mainly in the stomach and distributed in multiple lesions, mainly in the gastric sinus. Clinical symptoms are not obvious, mainly manifested as upper abdominal discomfort with indigestion symptoms such as bloating, early satiety, burping, nausea, and sometimes anemia. It is important to pay attention when suffering from gastritis and go to the hospital for gastroscopy to clarify the diagnosis and treat with medication under the guidance of a doctor.