【Objective】 To observe the treatment of Montelukast for respiratory syncytial virus (RSV) bronchiolitis on the clinical efficacy and the prevention of wheezing. 【Methods】 85 hospitalized children inflamed with RSV were randomly divided into treatment group and control group. Treatment group (45 cases) were ordered to oral montelukast in addition to conventional treatment. The usage was 2.5 mg/d under 6 months of age, and 4 mg/d in the children of 6 months elder, every night, the course of treatment were 2 months. The control group (40 cases) were treated with conventional treatment and with no special treatment in the post-discharge. The main symptoms and signs disappeared time, hospitalization, treatment efficiency and treatment for 2 months without respite days, 1 year recurrence rate of wheezing of the children in hospital were compared between the two groups. 【Results】 Comparing to the control group,the extinction time of main symptoms/signs and average hospital stays of the treatment group were significantly shorter (P<0.05), the therapeutic efficiency was significantly higher (P<0.05), Within 2 months of treatment the number of days without wheezing of the treatment group (42 cases) was significantly longer than the control group (38 cases) (P<0.05), the difference of 1 year recurrence rate of wheezing between treatment group (36 cases) and control group (35 cases) was not statistically significant (P>0.05). 【Conclusion】 Montelukast can improve the symptoms in the acute stage of RSV bronchiolitis,and prolong the time of RSV bronchiolitis without wheezing, but can not reduce recurrence rate within 1 year after treatment.