Clear saliva is actually our clear, normal saliva, and its an important body fluid for maintaining oral health. Saliva can also be called saliva, is a colorless and tasteless liquid mixture, saliva can also be regarded as the external environment of the teeth, which can play a rinse, buffer, antibacterial, antimicrobial and decomposition of the role of the mouth when the mouth by the stimulation of food or the nose smell stimulation is very easy to large amounts of secretion of saliva. At the same time, each person’s saliva secretion is not the same, some people secretion exuberant means that its salivary gland function is more developed, secretion of more saliva for the upper respiratory tract, the digestive tract surface lubrication and integrity of the maintenance is very important.