Objective: To analyze the efficacy and prognosis of fertility-sparing therapy of the patient with complex atypical hyperplasia (CAH) and endometrial cancer (EC). Methods: Clinical data of 191 EC and CAH patients who received fertility-sparing therapy in Peking University People's Hospital between January 2009 and September 2021 were recruited retrospectively. Outcomes of remission, recurrence and pregnancy were analyzed. Results: (1) Efficacy and efficacy-related factors: The complete response (CR) rate was 86.1% (161/187) for all the patients, and the CR rate of the CAH patients were higher than that of the EC patients (92.7% vs. 79.1%, P=0.007), the CR rate was significant higher in the CAH patients (OR=2.786, P=0.035). (2) The recurrence rate was 19.3% (31/161), and the recurrence rate of the EC patients were much higher than that of the CAH patients (26.4% vs. 13.5%, P=0.039). The median recurrence time was 22.5 (9.0, 50.0) months. (3) The high risk factors of recurrence were pathological type of EC (χ²=4.880, P=0.027), without the use of metfor-min (χ²=7.075, P=0.008), longer time to complete remission (>7 months) (χ²=6.204, P=0.013), and no pregnancy (χ²=6.765, P=0.009). (4) Results of pregnancy and related factors: Among the patients who achieved CR, 108 patients had fertility willing with the pregnancy rate of 41.7% (45/108), and the live birth rate was 34.3% (37/108). The live birth rate was lower in EC than that in the CAH patients (28.6% vs. 42.4%, P=0.045). The median time to achieve pregnancy was 10.50 (5.75, 33.25) months. The pregnancy rate was significant higher in the patients with pregnancy history (OR=9.468, P < 0.001) and in those who received assisted reproductive therapy (OR=7.809, P < 0.001). Conclusion: Fertility-sparing therapy of CAH and EC patients is effective resulting in high disease remission and certain pregnancy. However, the high recurrence rate and low pregnancy rate are still key problems for EC and CAH patients, therefore close monitoring and follow-up are indicated.