Abstract: Objective To observe and analyze the changes of C-reactive protein and inflam-matory factors in patients with obstructive sleep apnea syndrome.Methods 205 patients with ob-structive sleep apnea syndrome were divided into observation group Ⅰ (n =72),group Ⅱ (n =68) and observation group Ⅲ (n =65)according to apnea-hypopnea index (AHI),and the other 50 pa-tients were designed as control group.Levels of C-reactive protein,interleukin-6 and interleukin-18 were detected.Results The sicker,apnea-hypopnea index gradually increased (AHI),oxygen sat-uration decreased,C-reactive protein,interleukin-6 and interleukin-18 levels increased gradually. Logistic regression analysis showed that C-reactive protein,interleukin-6 and interleukin-18 and AHI,oxygen saturation were positively correlated with AHI and negatively correlated with oxygen saturation.Conclusion C-reactive protein level,interleukin-6 and interleukin-18 and other related inflammatory factors are the important indicators for prognosis judgment of patients with obstructive sleep apnea syndrome,so it is worthy of clinical application.