Four-month-old babies coughing with sputum in the throat is often seen in the upper respiratory tract infection, can be caused by viral or bacterial infections, according to the specific cause of the general care, medication and so on. Four-month-old babies coughing with sputum in the throat, may be upper respiratory tract infection, can be caused by viruses (such as respiratory syncytial virus, rhinovirus), generally do not need special antiviral drugs, cough sputum mucus can be used to use aminobromine nebulizer treatment. If the cough and sputum are sticky, it can be treated with aminoglutethimide nebulizer. If the infection is secondary to bacterial infection, it can be treated with antibacterial drugs (such as cefaclor). The medication also requires attention to daily care, such as reasonable feeding, pay attention to the feeding mode, avoid choking, keep the air clear. There may be other reasons why a four-month-old baby coughs with phlegm in his throat, so it is recommended to actively seek medical attention and be guided by a specialist. The medication should also be used under the guidance of a physician.