Usually, the endometrium of endometrial cancer patients is very thick, mainly because the endometrium of endometrial cancer patients has abnormal hyperplasia. However, some patients with endometrial cancer may not have thickened endometrium. Therefore, endometrial cancer endometrium is not necessarily thickened, and the thickness of endometrium varies at different ages. Most patients with endometrial cancer have thicker endometrium because endometrial cancer patients have abnormal endometrial hyperplasia. Endometrial cancer is a kind of gynecological malignant tumor, which tends to infiltrate and metastasize. It should be detected and treated in time, and it is recommended to visit gynecological department. There are individual patients with endometrial cancer whose endometrium may not appear thickened, especially focal endometrial cancer in situ. Patients mainly show abnormal uterine bleeding, which is mostly known through hysteroscopy or blind diagnostic scraping and sending to pathological examination. Therefore, the thickness of endometrium suggested by ultrasound alone cannot determine whether a patient has endometrial cancer, and hysteroscopy or curettage is necessary to make a clear diagnosis. In conclusion, endometrial cancer may not always have thick endometrium, and it is necessary to make specific judgment according to the examination and seek medical consultation timely when abnormalities are detected.