Cough with sputum is a common respiratory symptom in children and is commonly associated with acute upper respiratory tract infections, acute bronchitis, pediatric capillary bronchitis, bronchopneumonia and bronchial asthma. The duration of nebulization is related to the disease caused by the infection, the age characteristics and the immune function of the baby. Most of the nebulization is done for about 3 days, when the cough is relieved and the sputum can be easily coughed out. In two cases, the nebulization time is longer: First, the nebulization time is relatively long for infants and children, who do not cough and are prone to phlegm blockage in the throat, and need to do nebulization and aspiration when necessary, which may extend to about 1 week. Second, children with asthma or wheezing bronchopneumonia will take longer to do nebulization, at about 10-15 days.