The volume of seminal vesicles in the human body ranges from 4 to 5 ml, which generally varies from one individual to another. The seminal vesicles, also called seminal vesicle glands, are anatomically a pair of long oval sac-like vesicles, about 5 cm long and 1.0-2.0 cm wide, which are situated behind and above the base of the prostate gland, on the lateral side of the jugular of the vas deferens, and between the base of the bladder and the rectum. The total volume is 4-5 ml in volume. However, there are differences in the storage capacity of the seminal vesicles due to the presence of individual differences. Generally speaking, the function of seminal vesicles is mainly to secrete a weakly alkaliphilic yellowish viscous fluid, which accounts for 70% of semen, including fructose, various amino acids, fibrinogen, prostaglandins and citrulline, which has the function of nourishing and diluting spermatozoa. In addition to this the secretions of the seminal vesicles neutralize the acids in the vagina and the cervix of the uterus, thus maintaining the activity of the spermatozoa in the vagina and the uterus. Therefore, the presence of seminal vesicles is crucial for male reproduction and it is important to take care of their health.