Abstract: Objective: To evaluate the efficacy and safety of levocetirizine combined with montelukast in the treatment of chronic idiopathic urticaria(CIU) in children.Methods: Ninety-four children with CIU were randomly divided into the observation group(47 cases) and control group(47 cases).Two groups were treated with levocetirizine by oral for 28 days.The observation group were additionally treated with montelukast for 28 days.The efficacy in two groups were observed after 14 and 28 days of treatment using the scores of symptoms and signs,and the adverse events were recorded.All cases were followed up after 6 weeks and 12 weeks of stopping treatment.Results: The effective rates in observation group on 14th day and 28th day(74.5% and 87.2%) were higher than those in control group(55.3% and 70.2%),respectively(P<0.05).After treatment,the scores of symptoms and signs in two groups were obviously lower than those before treatment(P<0.01),and the wheal occurrence and duration in observation group were significantly less than those in control group on 14th day and 28th day(P<0.01).The recurrence rates in observation group after 6 weeks and 12 weeks of stopping treatment(12.8% and 17.0%) were lower than those in control group(29.8% and 36.2%),respectively(P<0.05).The incidence rates of adverse reaction in control group and observation group were 10.6% and 8.51%,respectively,and the difference of which between two groups was not statistically significant(P>0.05).Conclusions: Compared with levocetirizine,the treatment of CIU with levocetirizine combined with montelukast is safe,effective and less recurrence rate,which is worthy of popularization and application.