Capillary bronchitis is a lower respiratory tract disease caused by respiratory syncytial virus infection and other viral infections that occurs in winter and spring. It occurs in infants and young children, especially those between 2 and 6 months of age. In the early stage of infection, the child may have a mild cough without fever, and the symptoms may worsen in 2 to 3 days, with coughing and wheezing, especially in 2-month-old children, who may have poor spirit, cry more than once, do not eat milk, struggle to breathe, or even nod to breathe, have blue lips, have depressions in the chest breathing, and have wet rales and wheezing sounds in the lungs on auscultation. If the child has congenital heart disease, the risk is even greater, the current treatment is mainly to do drug nebulization, intravenous fluids, heavy to breathe oxygen, when the autonomic breathing difficulties will have to use the ventilator. Most of the children can be cured after a reasonable and active treatment, and most of them take about 10 days.