[ABSTRACT]OBJECTIVETo study the therapeutic efficacy of Montelucast and Cetirizine on allergic rhinitis in children and their effects on the level of serum IFN-γ and IL-4.METHODS Sixty allergic rhinitis children were randomly divided into treatment group (30 children) and control group (30 children). The control group were treated with cetirizine drops (po, ages 2-6, 5 mg, qd, ages >6, 10 mg, qd.). Treatment group were treated with cetirizine drops combined with Montelucast (po, ages 2-5, 4 mg, qn, ages 6-12, 5 mg, qn, ages >12, 10 mg.). Thirty health children were selected as health group.RESULTSBefore treatment, the level of serum IFN-γ in treatment group and control group were significantly lower than that in health group (P<0.01), but the level of serum IL-4 were significantly higher than that in health group (the F was 19.25 and 143.81 respectively;P<0.01). Before treatment, there was no significant difference in the level of serum IFN-γ and IL-4 between treatment and control group (P>0.05). After treatment, the level of serum IFN-γ of both groups increased, and the level of serum IL-4 of both groups decreased. However, the level of serum IL-4 and IFN-γ in treatment group changed significantly (P<0.01). After treatment, VAS scores were lower than that of before treatment, however that of the treatment group was the lowest (P<0.01). After one month follow-up, there was no significant difference between the two groups.CONCLUSIONThe mechanism of Montelucast and cetirizine on treatment of allergic rhinitis may be related to the correction of the disorder of IFN-γ and IL-4.