Abstract:  Objective    To study the effect of ubiquitin C-terminal hydrolase-L1 (UCH-L1) gene deletion on the reproductive system of female mice. Methods     Vaginal smears, immunohistochemistry, Western blotting and RNA interference methods were used to analyze the effects of UCH-L1 gene deletion on the ovarian function and follicle development in mice. Results    The adult female mice with UCH-L1 deletion had lower body weight, dyskinesia and thinner uterus. No UCH-L1 protein expression was detected in the ovaries and uteruses of UCH-L1-deleted homozygous mice, and the ovary volume was significantly smaller than that of heterozygous mice. There were some primitive or closed follicles in the ovarian cortex, and there was no mature follicle and corpus luteum. The key reproductive receptors including estrogen receptor (ER), follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR) and progesterone receptor (PR) were expressed in the ovary of UCH-L1-deleted homozygous and heterozygous mice. The expression level of ER in the ovary of UCH-L1-deleted homozygous mice was significantly lower than that of heterozygous mice. By RNA interference, knocking down the expression of UCH-L1 in germinal vesicle (GV) oocytes could significantly reduce the maturation rate of oocytes.