Abstract: ob＜x＞jective At present, the study on the function of seminal vesicle gland fluid is relatively mature, but its role in the process of sperm-egg union is poorly understood. In this paper, the function of seminal vesicle gland fluid in sperm-egg union is further studied by generating a mouse model of seminal vesicle gland resection. Methods 1. Mouse testicular tissue structure analysis: The seminal vesicle gland exposure and seminal vesicle gland resection mouse models were generated respectively, the morphology and weight of testes were observed, and morphological structure of the testicular lumen were used hematoxylin-eosin staining ( HE) analysis. 2. Sperm concentration and viability analysis: Computer-assisted semen analysis (CASA) is used to analyze its fertility-related parameters, including sperm motility and sperm concentration. 3. Fertility test: 8-week-old adult seminal vesicles exposed mice and seminal vesicles removed mice were mated with wild-type C57BL/6 female mice at a ratio of 1:1 male to female, maintain an observation period of 6 months, observe and record the number of litters, analyze the results. 4 . Observation of E6.5 embryos: the female mice were mated with the seminal vesicle gland exposure group and the seminal vesicle gland excision group at a ratio of 2:1, and the female mice that picked up the plug were placed alone, the embryos in the uterus were taken and counted 6 days later. V. In vivo fertilization experiment: 6 weeks old female mice were mate with seminal vesicle gland-exposed mice and seminal vesicle gland-exposed mice with 1:1 ratio cages to conduct in v ivo fertilization experiments. the pronucleus in vivo fertilization was obtaine d by surgery on the next day, record the development of the two groups embryos in vitro culture in real time. Results 1. Compared with the mice exposed to the seminal vesicle glands, there were no significant differences in the morphology, weight, and luminal tissue morphology of the seminal vesicles removed mice (P>0.05). 2. Sperm motility and concentration did not change significantly compared with the seminal vesicle exposure group of mice ( P>0.05). 3. The fertility test found that the seminal vesicle gland resection group male mice were sterile, and the seminal vesicle gland exposure group male mice gave birth to about 7 litters on average. 4. E6.5 embryos were not found in female mice mated with the seminal vesicle gland excision group. 5. In vivo fertilization experiments show that mice can be partially fertilized to form pronucleus after seminal ves icle gland removal, but unable develop into normal 4 cells. Conclusion Part of the sperm of the seminal vesicle gland removed mice can complete the fertilization and develop into 2 cells, but unable form the normal 4 cells, which eventually leads to infertility.