Abstract: Objective: To investigate the correlation between allergic rhinitis and obstructive sleep apnea-hypopnea(OSAHS) syndrome in children.Method: ①According to medical history, physical signs, skin-prick test, serum sIgE, endoscopic examination and polysomnography, the incidence of allergic rhinitis was confirmed in 574 cases of childhood obstructive sleeping apnea-hypopnea syndrome in our hospital between July in 2008 to June in 2010. ②Effects of anti-allergic drugs were observed on 78 children with OSAHS and allergic rhinitis meanwhile.Result: ①258 cases of allergic rhinitis were confirmed in 574 cases of OSAHS, accounting for 44.9% of the OSAHS cases and 50.4% of all cases of allergic rhinitis during the same period. Most of them were perennial allergic rhinitis(223 cases,86.4%), and 72.5% of them were aroused by fungal allergen. Compared with other allergen, statistically significant difference was found(P＜0.05).②After receiving anti-allergic drugs regularly for 3 weeks, 40 cases suffering from mild and moderate OSAHS and allergic rhinitis, 3 cases out of 38 cases suffering from serious OSAHS and allergic rhinitis showed satisfactory results, while other cases had little improvement.Conclusion: Allergic rhinitis is closely related to childhood OSAHS, and perennial allergic rhinitis dominates. The most common allergen is fungal allergen, the second is house and flour dust mites. So for patients of mild and moderate OSAHS with allergic rhinitis, regular anti-allergic drugs can lighten OSAHS effectively and may make patients avoid surgery. Severe OSAHS cases can receive surgical intervention if prior anti allergic therapy fails. Anti allergic therapy should be adopted routinely after tonsillectomy and adenoidectomy in case of hypopnea due to hypertrophy of inferior turbinate or tubal torus in allergic rhinitis.