Drooling at the corners of the mouth is a normal physiological phenomenon in infants, but it may also indicate the presence of oral diseases, neurological diseases, and if accompanied by other discomforts, it is recommended to consult a doctor in a timely manner. 1. Physiological phenomenon: most infants in 5 to 6 months due to increased salivary secretion, and swallowing regulation of the function is not yet perfect, thus triggering the phenomenon of drooling at the corners of the mouth. In addition, young children within 2 years of age, when the eruption of milk teeth, this symptom can also occur. 2. Oral diseases: such as stomatitis, oral ulcers, oral foreign bodies, etc., the patient may also be accompanied by local redness, swelling, heat, pain, fever and other symptoms. 3. Neurological diseases: such as congenital cerebral hypoplasia, Parkinson’s disease, facial nerve palsy, etc., patients may also be accompanied by crooked corners of the mouth, mouth and lips can not be closed, motor disorders, sensory disorders and other discomforts. Patients with drooling at the corners of the mouth, if accompanied by other discomforts, it is recommended to consult a doctor in time to identify the cause of the disease, and follow the doctor’s instructions for appropriate treatment.