More than three months baby drooling may be physiological factors, may also be the manifestation of certain diseases, such as oral diseases, digestive discomfort, brain dysplasia, etc., should be timely consultation to identify the cause. 1. Physiological factors: because the three-month-old baby, the oral cavity is relatively shallow, mouth and tongue movement at this time began to increase, and the ability to swallow is relatively poor, the salivary glands began to increase the secretion of the mouth, there is no way to the mouth inside the excessive saliva to swallow, there will be the phenomenon of drooling. 2. Pathologic factors: (1) oral disease: such as goose mouth, mouth ulcers, etc., will cause children more crying, eating significantly reduced, refusing milk and other phenomena. (2) Digestive discomfort: children who may experience digestive discomfort may also experience increased drooling accompanied by anorexia. (3) Brain dysplasia: When babies have brain dysplasia, such as cerebral palsy, prematurity encephalopathy, etc., it is easy to lead to uncoordinated swallowing as well as mouth opening, so they are prone to drooling. If physiological causes are ruled out, timely consultation should be made to ask the doctor to clarify the cause and give targeted treatment.