The vagina is a unique female reproductive organ located between the urethra and the anus. It is very important for women, not only as a channel for the discharge of menstrual blood, but also for sexual intercourse and for the delivery of the fetus. The vagina is slightly flattened from front to back and the vaginal wall is made up of a fibrous layer and a mucosal layer, with a light red mucosa. The normal length of the vagina is slightly shorter than the posterior wall, with the anterior wall being 7-9 cm and the posterior wall usually 10-12 cm, while the width can usually accommodate two fingers, but the vagina is particularly contractile. Women should pay attention to the hygiene of the perineum and wash it with warm water every day to avoid infections such as vaginitis. Both men and women should have good sexual hygiene during sex and wear loose underwear to avoid impermeability.