PURPOSE: To describe the temporal trend of endometrial burden in postmenopausal women aged 55 years and above worldwide from 1990 to 2021, evaluate the age cohort effect, explore its influencing factors, and predict the disease burden in the next 15 years. PATIENTS AND METHODS: Using Joinpoint regression, data from the 2021 Global Burden of Disease Study were assessed for changes in endometrial cancer incidence rate, morbidity, and mortality in postmenopausal women aged 55 years and above. Age period cohort analysis helped estimate age, period, and cohort effects. The Das Gupta method helped analyze effects of different factors on endometrial cancer incidence and mortality among postmenopausal patients. ARIMA helped predict the endometrial cancer disease burden in postmenopausal women from 2022 to 2036. RESULTS: In 2021, globally, there were 360253 (326,176-388545) cases and 84630 (75,523-93215) deaths among postmenopausal patients with endometrial cancer. During 1990-2021, the global endometrial cancer incidence in postmenopausal women gradually increased, while the mortality rate gradually decreased. Changes in disease incidence and mortality rates are mainly due to population growth and epidemiological changes, with little influence of age. The risk of endometrial cancer in postmenopausal women gradually increased with age, using age, period, and cohort average as the reference groups. The mortality rate decreased gradually decreased in 2019 and continued to rise thereafter. It is expected that by 2036, the incidence of endometrial cancer in postmenopausal women aged 55 years and above will increase by 6.5%, and the mortality rate will decrease by 8.0%. CONCLUSION: The number of patients with postmenopausal endometrial cancer aged 55 years and above is still increasing, and it is necessary to establish a comprehensive screening and treatment mechanism to ensure prolongation of patient lifespan.