Objective: To investigate the risk factors alert mechanism in children with obstructive sleep apnea and hypopnea syndrome (OSAHS), and to determine the correlation of arousal and systematic inflammation response. Methods: Two hundred and eighty-five cases of snoring children aged 6-11 years old were included, sleep questionnaires were completed by their parents. All the children performed the whole night polysommongraphy (PSG), the total sleep time (TST), sleep efficiency, sleep structure, oxygen desaturation, and various respiratory disorder index were assessed by physician. Thirty children at high risk and low risk for obstructive sleep apnea syndrome (OSAHS) were randomly selected to detect the blood routine, C reactive protein (CRP) and interleukin-1β (IL-1β) levels. Results: Fifty-six cases (19.6%) of snoring children were diagnosed OSAHS by PSG. Logistic regression analysis showed that tonsil and adenoid hypertrophy, habitual snoring, obesity, mouth breathing, enuresis, hyperactivity and irascibility were the main risk factors. PSG study showed that TST, sleep efficiency, deep sleep (stage III and IV) and REM sleep time decreased, light sleep (stage I and II), arousal index (AI), OAI, AHI and RDI increased in OSAHS children. IL-1β and CRP levels increased in OSAHS children. Pearson correlation analysis showed there was positive correlation between AI and RDI (r=7.56, P<0.01). Furthermore, AI correlated with the level of IL-1β (r=6.85, P<0.01). Conclusion: Tonsil and adenoid hypertrophy, habitual snoring, obesity, mouth breathing, enuresis, hyperactivity and irascibility are the main risk factors of OSAHS children. AI increases in accord with RDI and this phenomenon may correlate with systematic mild inflamation reponse.