Abstract: 【Objective】 To study the histomorphological changes of the reproductive organs after superovulation in prepubertal mouse models,and to provide a theoretical reference for the implementation of superovulation in domestic animals.【Method】 Twelve prepubertal mice and twelve adult mice of the same body weight were randomly divided into control group and experimental groups,with 6 mice in each group.After hormonal superovulation treatment,gross anatomy,tissue sections and transmission electron microscopy were combined to analyze the morphological differences of the reproductive organs between prepubertal and adult mice.【Result】 The adult superovulated group had a significantly lower number of corpus lutea than the prepubertal superovulated group（P＜0. 05）,but a significantly higher area and diameter of the corpus luteum than the prepubertal superovulated group（P＜0. 01）. Ultrastructure showed abundant lipid droplets in granular luteal cells and membranous luteal cells,and the granular luteal cells in the adult superovulated group were more closely arranged than those in juvenile superovulated group. Compared with that of the adult control group,the uterine cavity epithelium in the adult superovulated group was significantly rolled up. In addition,the uterine horn width,uterine body width,uterine horn area and uterine horn diameter of the adult superovulated group were significantly lower than those of the adult control group（P＜0. 01 or P＜0. 05）. Uterine horn diameter,circular muscle layer thickness and longitudinal muscle layer thickness of the prepubertal mice in the superovulated group were significantly higher than those of the prepubertal mice in the control group（P＜0. 01 or P＜0. 05）.【Conclusion】 Compared to adult mice,prepubertal mice ovulate more frequently,but they produce a smaller area of mature follicles,which may affect the quality of the eggs. The uteri of adult and prepubertal mice respond differently to hormones that induce superovulation.