Objective:To study the clinical effects of modified surgical method with H-uvulopalatopharyngoplasty(H-UPPP)and traditional surgical method in the treatment of obstructive sleep apnea hypopnea syndrome(OSAHS)in children.Methods:The clini-cal data of 364 pediatric patients with OSAHS were retrospectively analyzed.The patients were divided into 2 groups and treated by low-temperature plasma knife radio frequency ablation for bilateral tonsil removal combined with H-UPPP(group A,n=204)and low-temperature plasma knife radio frequency ablation only(group B,n=160)respectively.The operative time,intraoperative bleed-ing,postoperative secondary bleeding,VAS of pain following operation,postoperative traumatic white film shedding time,OAH1,LSaO2,ESS scores and complications of the 2 groups were compared.Results:In group A the operative time,intraoperative bleed-ing,VAS,OAHI and ESS scores were lower than those in group B(P＜0.05),wile postoperative traumatic white film detachment time and LSaO2 were higher(P＜0.05).No statistically significant difference in terms of the number of cases of postoperative seconda-ry bleeding and complications was observed between the 2 groups(P＞0.05).Conclusion:The combination of low-temperature plas-ma radio frequency ablation and H-UPPP for the treatment of OSAHS may provide clear intraoperative view,and may improve the treatment effects.