Whether gastric polyp can become cancerous and how soon it becomes cancerous are related to the type of polyp and need to be analyzed specifically. Gastric polyp can be divided into tumor polyp such as adenomatous polyp and non-tumor polyp such as hyperplastic polyp and inflammatory polyp. Non-neoplastic polyps are basically benign lesions and usually do not become cancerous. The cancer rate of adenomatous polyps is related to the size of polyps, the smaller the diameter of polyps, the lower the cancer rate. In general, gastric polyps are small, less than 1 cm, and the cancer rate is generally 1.0%. In contrast, when the diameter is more than 2 cm, the cancer rate can reach 35%, and the average time is 5-10 years. In addition, adenomatous polyps have the possibility of cancer, which can be prevented if they are detected and removed in time. When patients have symptoms such as epigastric discomfort, nausea, loss of appetite or black stool, they should go to the hospital for gastroscopy to determine the cause in time. Therefore, when patients are diagnosed with polyps by gastroscopy, pathological examination should be done and removed, and attention should also be paid to review to prevent polyps from recurring.