Coupling agent is consumable supplies, can not be used repeatedly, hospitals use is generally a large bottle of common type coupling agent, so mostly shared. Coupling agent is a medical product composed of a new generation of water-based polymer gel, its PH value is neutral, non-toxic and harmless to the human body, not easy to dry, not easy to rancidity. The use of coupling agent in ultrasound examination can make the probe and the body in close contact, to avoid the gas and the body surface of the natural depression on the results of the examination. Coupling agent is an ultrasound examination with the help of a thing, can make ultrasound examination imaging clear, viscosity is appropriate, not greasy, the probe is easy to slide, can wet the skin, exclude the air on the surface of the skin, lubrication performance is good, easy to apply; no corrosion, no damage to the ultrasound probe. The coupling agent is harmless to human skin and is clean. After the examination, use a tissue or towel to wipe the coupling agent applied to the examination area can be. The coupling agent is single-use and cannot be used repeatedly. However, some hospitals currently use large bottles of common type coupling agent, which are usually used for public use because of the large quantity.