Saline, also known as sterile saline, is a 0.9% sodium chloroargonate solution with an osmotic pressure essentially equal to that of human blood. The main effect is to replenish body fluids and maintain electrolyte balance. It is used to dissolve drugs and clean wounds. Saline is a sodium chloride solution with osmotic pressure basically equal to that of human blood. In clinical practice, it is mainly used as a dissolving agent for injectable drugs to avoid direct injection of drugs to destroy the electrolytes at the injection site. In addition, it can also be used as a rehydration and sodium replenishment drug, both rehydration and maintenance of electrolyte balance. Saline is also often used for trauma and burn wound cleaning, used to thoroughly clean the trauma stains and foreign bodies, after the bandage and other late treatment. It should be noted that the use of saline should be carried out under the guidance of a doctor, can not be used without authorization, in order to avoid the use of improper consequences.