Most endometrial cancers (EC) are diagnosed at an early stage with a favorable prognosis. However, for patients with advanced or recurrent disease, the chemotherapy response rate and overall survival remain poor. A novel in vitro model, tumor organoids, has important value in providing a more individualized treatment plan for tumor patients. However, the slow growth of the established EC organoid seriously hinders the application of EC organoids. Cancer-associated fibroblasts (CAFs), the main component of tumor stroma, have been reported to promote the proliferation of endometrial cancer cell lines and primary endometrial cancer cells in vivo and in vitro. Therefore, we optimized the current endometrial cancer organoid by introducing CAFs isolated from EC lesions. Here we developed long-term expandable organoids from endometrial cancer lesions, which show disease-associated traits and cancer-linked mutations. Based on the co-culture of CAFs and endometrial cancer organoids, we found that CAFs could promote the growth of endometrial cancer organoids, might by secreting factors according to the result that CAFs could also promote the growth. Our research provided a more promising model for the basic and preclinical study of endometrial cancer.