OBJECTIVE： To explore the clinical efficacy and safety of Leukotriene receptor antagonist combined with Glucocorticoid nasal spray （called “intranasal steroid” for short） in the treatment of different degree of adenoidal hypertrophy （AH） complicated with allergic rhinitis （AR）. METHODS： 240 AR children with AH were randomly divided into control group， intranasal steroid group and drug combination group， with 80 cases in each group. Control group was given physiological seawater， 3 presses each nostrile， in the morning and evening. The intranasal steroid group received Momestasone furoate nasal spray， one press each nostrile， qd. Drug combination group was additionally given leukotriene receptor antagonist Montelukast sodium chewable tablet， 4 mg for under 5 year-old and 5 mg for 5-year-old or above， qd， at bedtime. Treatment course of 3 groups lasted for 12 weeks. The change of clinical symptoms and signs （such as nasal obstruction， snore， mouth breathing， etc） and adenoid/pharyngeal ratio（A/N ratio）were compared among 3 groups after treatment as well as the occurrence of ADR. Each group was divided into two sub-groups （medium and severe） according to the severity of AH so as to evaluate therapeutic efficacy. RESULTS： 21 children withdrew from the study， including 11 cases in control group， 6 in intranasal steroid group and 4 in drug combination group. After treatment， clinical symptom score and A/N in subgroups of drug combination group and intranasal steroid group were all lower than those of control group， with statistical significance （P＜0.05）. There was no statistical significance in clinical symptom score and A/N between drug combination group and AR complicated with medium AH subgroup from intranasal steroid group （P＞0.05）. Clinical symptom score and A/N of AR complicated with severe AH subgroup from drug combination group were lower than intranasal steroid group， with statistical significance （P＜0.05）. No obvious ADR occurred in 3 groups. CONCLUSIONS： Intranasal steroid alone and intranasal steroid combined with leukotriene receptor antagonist can improve clinical symptom of AR patients with AH，and reduce adenoid volume. It is suggested to use intranasal steroid firstly for medium AH complicated with AR， and additionally use Leukotriene receptor antagonist for severe AH complicated with AR.