<p>Intrauterine adhesion (IUA) is a disease caused by endometrial damage without effective treatments. Stem cell therapy has been initiated as a new attempt to repair and regenerate injured tissues. However, the therapeutic efficacy of stem cell therapy is limited. Kaempferol is a natural flavonoid with various beneficial effects. In this study, our goal is to investigate the roles of kaempferol combined with umbilical cord-derived mesenchymal stem cells (UCMSCs) in IUA. UCMSCs were collected from human umbilical cords. The multilineage differentiation potential of human UCMSCs was evaluated by Oil Red O staining, Alizarin Red S staining, and Alcian Blue staining. The phenotype profile of human UCMSCs was assessed by flow cytometry. CCK-8 and Transwell assays were performed to detect cell viability and migration. The IUA rat model was established. Histological changes were examined by hematoxylin–eosin staining and Masson staining. Gene expression was evaluated by western blotting and immunofluorescence. Kaempferol (10&#xa0;μM) promoted the migration and proliferation of human UCMSCs in vitro. Additionally, kaempferol/UCMSCs combination treatment recovered endometrial injury and inhibited endometrial fibrosis and epithelial-mesenchymal transition occurrence in IUA rat models. Mechanistically, kaempferol/UCMSCs combination treatment inhibited JAK2/STAT3 pathway. Kaempferol/UCMSCs combination treatment can promote the repair of damaged endometrium by decreasing endometrial fibrosis. The inactivation of JAK2/STAT3 pathway is greatly responsible for the protective effect of kaempferol/UCMSCs combination treatment.</p>