ObjectiveTo systematically review the efficacy of umbilical cord mesenchymal stem cells in the treatment of premature ovarian failure. MethodsCNKI, WanFang Data, SinoMed, PubMed and EMbase databases were electronically searched to collect animal experiments of the efficacy of umbilical cord mesenchymal stem cells in the treatment of premature ovarian failure from inception to September 17th, 2021. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies; then, meta-analysis was performed by using RevMan 5.4.1 software. ResultsA total of 9 studies involving 302 mice were included. The results of meta-analysis showed that: umbilical cord mesenchymal stem cell transplantation could increase primal follicles (SMD=1.51, 95%CI 0.80 to 2.22, P<0.000 1), primary follicles (SMD=1.43, 95%CI 0.76 to 2.09, P<0.000 1), secondary follicles (SMD=1.39, 95%CI 0.78 to 2.01, P<0.000 01) and sinus follicles (SMD=1.15, 95%CI 0.49 to 1.82, P=0.000 7). It significantly increased the concentration of estradiol in rats with premature ovarian failure (SMD=2.38, 95%CI 1.75 to 3.01, P<0.000 01), and decreased serum follicle-stimulating hormone concentration (SMD=?1.98, 95%CI ?2.80 to ?1.17, P<0.000 01). ConclusionCurrent evidence shows that umbilical cord mesenchymal stem cell transplantation can repair ovarian tissue and improve ovarian endocrine function in mice. Due to limited quality and quantity of the included studies, more high-quality studies are needed to verify above conclusions.