Gastric ulcer malignancy, mainly refers to the occurrence of atypical hyperplasia of the gastric mucosa on top of the ulcer base, which is categorized into mild, moderate and severe. When severe atypical hyperplasia is reached, it will lead to atypical deterioration of the mucosa, which can be manifested as imprinted cellularity or highly differentiated or poorly differentiated adenocarcinoma. If adenocarcinoma is present, most of them will have metastasis in the muscular or submucosal layer of the mucosa, and some of them will have metastasis in the peripheral lymph nodes. Once metastasis occurs, it is easy to metastasize to the liver or the lungs, and other parts of the body will have multi-organ malignancies. If accompanied by metastasis, most of the disease has reached the manifestation of advanced stage. Gastric ulcers, especially in the gastric sinus, gastric angle of the ulcer, this situation is also prone to the possibility of malignant transformation, the need to actively give ulcerative treatment, but also need to review the gastroscope regularly, when necessary to take the pathology, histological examination to assist in the diagnosis.