【Objective】 To explore the effect of montelukast on the treatment of airway inflammation in the bronchiolitis after respiratory syncytial virus (RSV) infection by studying the clinical manifestations and change of serum concentration of inflammatory cellular factors including interleukin-5(IL-5) and eotaxin. 【Methods】 88 infants with bronchiolitis caused by primary infection of RSV associated with atopy (1 eczeca,family asthmatic history ) were recruited in the study and they were randomly divided into two groups, forty cases were selected as the control group treated with conventional therapy. 48 cases were treated with montelukast in addition to conventional therapy.Blood samples were collected on the first day on admission before treatment and recovery phase of the disease. Follow-up was done to observe recurrence for 3 months. 【Results】 IL-5 and Eotaxin level in patients during acute phase of the desease were significiantly higher than those during recovery phase, the level of Il-5 and eotaxin were decreased distinctly by montelukast.moreover . The differences in patients with reccurrence of wheeze between trial groups and control groups were significant. 【Conclusion】 Montelukast may decrease the serum concentrations of IL-5, eotaxin and control airway inflammation in the bronchiolitis after RSV, it may play a role in the prevention of recurrence attacks of wheeze after bronchiolitis.