The posterior vaginal fornix is an anatomical location in the female genital tract, located primarily at the tip of the vagina, behind the cervix, called the posterior vaginal vault. The posterior vaginal vault is often clinically a little deeper than the anterior fornix, and semen is usually stored in this area, where it will naturally flow to the posterior fornix after intercourse. In case of a retroflexed and retroverted uterus, the cervix will be close to the anterior vaginal wall at this time, so it is recommended to rest on the bed for 1 hour after intercourse, and the semen will soak up the cervix, increasing the chances of pregnancy. In addition, there will be a lot of secretions in the posterior vaginal fornix. It is recommended that if secretions are taken for examination, they are taken in the posterior fornix for laboratory tests.