Abstract: Objective To observe the clinical efficacy of surgeries on treatment of children with obstructive sleep apnea hypopnea syndrome (OSAHS)so as to explore the main pathogenic fac-tors and the primary causes influencing surgical efficacy.Methods A total of 85 children with OS-AHS were selected and given surgical therapies to observe the comprehensive efficacy and analyze the relevance between hypertrophy degrees of tonsils and adenoids with apnea index (AI),apnea hy-popnea index (AHI)and the lowest arterial oxygen saturation (LSaO2)before and after treatment. Results After operation,the recovery rate of all children was 90.59%,and the mean values of AI, AHI and LSaO2 were evidently better than treatment before (P <0.01).There was no significant difference in AI before treatment while AHI was in positive relation but LSaO2 in negative associa-tion with hypertrophy degree of tonsils,and AI,AHI and LSaO2 were improved markedly 2 months after treatment than treatment before (P <0.05 or P <0.01).Before operation,adenoid group in degree Ⅱ was obviously lower in AI and AHI but apparently higher in than adenoid group in degreeⅢ (P <0.01);after treatment,AI,AHI and LSaO2 were evidently better than treatment before (P < 0 .0 1 ),and better in adenoid group in degree Ⅱ than in adenoid group in degree Ⅲ (P <0.01).Conclusion The main cause of children with OSAHS is nasopharynx airway stenosis, whose severity is in close association with airway stenosis degree ,for which the surgeries can effectively remiss the condition,improve respiratory function and eliminate or even resolve the clinical symptoms.