The labia majora and labia minora are relatively easy to distinguish, the labia majora are located on the outside and have pubic hair, and the labia minora are located on the inside and have no pubic hair. The labia majora is a pair of close to the inner side of the two females, longitudinal elevated elastic skin folds, the two sides of the labia majora anterior and posterior end of the joint, respectively, to form the lips before the joint and after the joint lips, the labia majora is usually closed, covering the urethral opening and the vaginal opening. The labia majora are rich in subcutaneous fat, rich in blood vessels, lymph and nerves, when sexually aroused, the labia majora open from the midline to both sides, exposing the vaginal opening. The labia minora are located on the inner side of the labia majora, a pair of thin skin folds, the surface is smooth, moist, hairless, the posterior end of the labia minora on both sides of the labia minora meet with each other to form the labia minora, the labia minora on the front end of the labia minora each form two small folds, the outer one in the clitoris on the dorsal side of the clitoris connected to the inside to become the clitoral periosteum, the inner one in the clitoris under the clitoris with the opposite side of the conjunction, upward to connect to the clitoris, constituting the clitoral tie.