After a lot of clinical studies, it is believed that endometrial hyperplasia is very closely related to endometrial cancer. Firstly, both are related to the patient’s long-term estrogen stimulation, that is, they are related to the level of estrogen in the patient’s body. Second, in terms of pathological patterns, both have glandular hyperplasia, but differ only in terms of the glandular and cellular differentiation of the hyperplasia. Some atypical hyperplasia of the endometrium can develop into endometrial cancer, and if endometrial atypical hyperplasia develops into cancer, it is often a long process. Among the 4 patients reported from Peking Union Medical College Hospital, 3 cases exceeded 5 years, the longest 2 cases were 10 and 15 years, and the shortest l case was 3.5 years. The other reported cases also had a disease course between 8 and 15 years. Shorter times have also been reported. However, it is not true that all atypical hyperplastic endometrium can develop into endometrial cancer; some of them can be transformed into normal endometrium under the effect of exogenous hormones such as progesterone. With aggressive drug treatment for endometrial atypical hyperplasia, most endometrium responds well and has a good prognosis. However, there are still some cases that may recur, and there is a possibility of reconversion to cancer in individual patients. This tendency of recurrence may be related to the persistent high level of estrogen in the body for a long time, which has not been completely corrected. Therefore, it is still necessary to review regularly after treatment. Hysterectomy should be performed as early as possible if the treatment is not effective and there is a tendency of early cancer.