Children running clear nose suggests inflammation of the nasal mucosa, or allergies caused by increased secretion so runny nose. If the runny nose for a long time into yellow snot, generally speaking should be secondary infection, secondary bacterial infection is common, this situation should go to the hospital for examination, at least should be a routine blood test, C-reactive protein to understand the status of infection. If there is a basis for bacterial infection, usually need to take anti-infective drugs, commonly used cefaclor granules, etc., should also take measures, such as buying saline nasal spray to clean nasal secretions; if the child has allergic factors also need to take appropriate anti-allergy drugs, such as loratadine or cetirizine hydrochloride drops, and so on. If there is a history of chronic rhinitis, sinusitis, but also need to see the ENT clinic, for the original disease for active treatment, the baby runny nose into yellow snot in order to get complete control of the situation.