authors contributed equally to this work. AbstractFemale fertility is the capacity to produce oocytes and achieve fertilization and pregnancy, and these outcomes are impaired by age, diseases, environment and social pressure. However, there is no effective therapy that preserves female reproductive ability. Mesenchymal stromal cells (MSCs) can exhibit multidirectional differentiation potential, and they have gained great attention as a tool for preserving female fertility.Therefore, this study uses human umbilical cords-MSCs (Huc-MSCs) to preserve and restore fertility in aging female mice and chemotherapy-damaged mice through the rescue of ovarian function and the reconstruction of the fallopian tubes and uterus. In our study, 2 mouse models were generated: aging mice (37 weeks old) and chemotherapy-damaged mice. Then, we injected Huc-MSCs into mice through the tail vein. After treatment, the effect of MSCs on the ovary, fallopian tubes and uterus was evaluated by analyzing gonadal hormone levels and by performing morphological analysis and statistical analysis. The levels of E2 and FSH exhibited a significant recovery after HUC-MSC transplantation both in aging mice and mice treated with chemotherapy. Huc-MSC treatment also increased the numbers of primordial, developing and preovulatory follicles in the ovaries of mice. Meanwhile, MSCs have been shown to rescue the morphology of the fallopian tubes and uterus through mechanisms such as regenerating the cilia in fallopian tubes and reforming glands and chorionic villi in the uterus. Therefore, it is suggested that Huc-MSCs may represent an effective potential treatment for preserving female fertility through recovery from chemotherapy damage and rescuing female reproductive organs from the effects of aging.