OBJECTIVE To study the relationship between the level of high sensitive C-reactive protein (hs-CRP)and obstructive sleep apnea/hypopnea syndrome(OSAHS)in children. METHODS Between 2008 and 2009, 30 children who were diagnosed OSAHS, were enrolled in OSAHS group. Thirty children with a history of chronic tonsillitis made up chronic tonsillitis group. Thirty children(27 children were diagnosed accessory auricle and 3 children with laryngeal web)consisted of the control group. The three groups were matched by age, sex and BMI. Children in OSAHS group underwent overnight polysomnography monitoring in our medicine sleep center. Samples for plasma hs-CRP level were collected in the morning. RESULTS 1. The difference of plasma hs-CRP level among three groups was not significant (?2=0.179,P=0.914). 2. Plasma hs-CRP level did not correlated with AHI, BMI and lowest saturation of blood oxygen(rs=0.343, 0.104 and-0.062; P=0.064, 0.584, and 0.747, respectively). CONCLUSION Higher hs-CRP values were not observed in children with OSAHS. There are no correlation between hs-CRP and AHI, BMI and lowest saturation of blood oxygen.