Surgery is the primary treatment for endometrial cancer and is required for many endometrial cancer patients. Surgery requires removal of the uterus, ovaries, and removal of lymph nodes is the basic scope. Many patients don’t understand “Why do we need to clear the lymph nodes?” 1.Because the first station for cancer cells to metastasize is the adjacent lymph nodes. If the lymph nodes have been metastasized and not cleared, only the cancerous tissues are cut, then the disease will recur soon. 2, Lymph nodes are the body’s sentinels, and if there is a viral or bacterial infection or cancer cell invasion, it will swell. Although imaging tests such as ultrasound or CT or MRI have been done before surgery, the lymph nodes may not be enlarged obviously and it is not 100% certain whether they have metastasis or not. Therefore, intraoperative lymph node dissection is also done to clarify the staging and diagnosis. Warm tips: the scope of lymph node dissection needs to be determined according to the condition.