Coughing is a common symptom of upper respiratory tract infections, and when there are secretions in the respiratory tract, coughing with phlegm can occur. When a baby coughs with phlegm, we first need to clarify what causes the cough? First of all, when a child has a cough with phlegm, it is mainly caused by infection. When it is clear that the infection is bacterial, viral or mycoplasma, antibacterial drugs should be actively used according to the type of infection, for example, for mycoplasma infection, macrolide antibiotics, such as azithromycin, can be used. Once the infection is controlled, the symptoms of coughing and phlegm can also disappear quickly. Secondly, when a baby coughs with phlegm, we can use phlegmolytic drugs to help dilute the phlegm and promote its discharge. Commonly used oral phlegmolytic drugs include Ambroxol hydrochloride oral solution and Fullux granules. Gastric mucous membrane stimulating effect, can help the child through vomiting and other ways to achieve the purpose of clearing phlegm. For some children with high airway reactivity, active anti-allergic treatment, together with phlegm-reducing drugs, can also achieve good results. If the cough with phlegm is caused by gastroesophageal reflux, then we need to identify the causative factors and take appropriate medications, etc. to improve the symptoms. Pediatric cough with phlegm is a common manifestation, and when actively treating phlegm, we must clarify what causes the cough with phlegm, and it is very important to actively treat the primary cause.