Objective: To analyze the clinical characteristics of autoimmune gastritis associated diseases, and review the related literatures so as to provide reference for clinical practice. Methods: Three cases of autoimmune gastritis were diagnosed by endoscopy and serological examination due to gastrointestinal symptoms accompanied with anemia, gastric neuroendocrine tumor or abnormal index of liver function respectively, and the correlation between autoimmune gastritis and associated diseases was explore. Results: Case 1 presented with " nausea accompanied by intermittent vomiting and anemia for 1 month", and serological examination indicated megaloblastic anemia postoperative pathology of gastric hyperplasia lesions showed local high-grade neoplasia tubular adenoma after admission. Case 2 presented with "repeated middle and upper abdominal discomfort for several months". Postoperative pathology of gastric hyperplasia lesions was neuroendocrine tumor (G1 stage) after admission to hospital. Case 3 presented with "abnormal index of liver function", and liver biopsy confirmed the diagnosis of primary biliary cholangitis after admission to hospital. Due to the thin mucosal layer of fundus and submucosal vessel penetration of gastric mucosa atrophy, chronic atrophic gastritis was observed in gastric pathology in all patients. Therefore, all serum tests showed positive results for endogenous factor antibody and parietal cell antibody, and all patients were diagnosed as autoimmune gastritis. Subsequent literature analysis suggested that autoimmune gastritis was associated with the development and progression of megaloblastic anemia, neuroendocrine tumor, primary biliary cholangitis and so on. Conclusions: Three cases reported were treated as megaloblastic anemia or gastric neuroendocrine tumor or abnormal index of liver function on first visit, and subsequently were diagnosed as having autoimmune gastritis. Attention should be paid to autoimmune gastritis associated diseases.