objective to investigate the relationship between the level of serum S100A1 and OSAHS complicated with acute respira-tory failure, so that in the intensive rescue of OSAHS we can make early recognition and treatment of acute respiratory failure situation. Methods 103 inpatients with OSAHS were divided into two groups, the experimental group including 63 cases complicated with acute respiratory failure, the simple group including 40cases with OSAHS alone, In addition choose 37 healthy people as control group. the level of S100A12, TNF- α, IL- 8, hs CRP were determinated and the relationship between S100A12 and OSAHS complicated with acute respiratory failure.Results The level of S100A12, TNF- α,IL- 8,hs- CRP,in experimental and simple group were higher than that of control group,The difference was statistically significant(P<0.05);The level of S100A12, TNF- α,IL- 8,hs- CRP,in the experimental group was higher than that of the simple group,The difference was statistically significant (P<0.05);Spearman rank correlation analysis revealed that the level of serum S100A12 was positively related with TNF- α、IL- 8、hs- CRP(r=0.238,0.363,0.210,P<0.05).Con-clusion the level of serum S100A12 is positively related to the incidence of acute respiratory failure,the level of serum S100A12 is one of the important risk factors for OSAHS complicated with acute respiratory failure.