Nine-month-old baby’s nose is not ventilated, considering that it may be a respiratory viral infection, or allergy caused by nasal mucosa congestion leading to nasal non-ventilation. Treatment treatment attention to the following points: first, you can use a piece of warm towel on the bridge of the baby’s nose above, the nasal cavity may be self-ventilating. Second, you can properly massage both sides of the bridge of the baby’s nose, the nose may also be ventilated. Third, you can buy saline nasal spray to clean nasal secretions, 2-4 times a day. Fourth, if the nasal congestion is serious or the baby himself has allergic rhinitis, sinusitis, can be anti-allergy treatment, such as oral loratadine, cetirizine hydrochloride drops, at the same time, to avoid the child to enter the environment that is easy to be allergic to, but also to avoid intake of food that is easy to be allergic to, such as eggs, seafood and so on.