Objective:To study the effect of N-acetylcysteine(NAC)on cardiocytes injury induced by chronic intermittent hypoxia (CIH) by establishing an animal model of obstructive sleep apnea syndrome(OSAS). Methods:Thirty-three ICR mouse were divided into 3 groups randomly:control,CIH and NAC groups. Malondialdehyde(MDA) and superoxide dismutase(SOD) in the cardiocyte homogenates were measured before and after the treatment of NAC using thiobarbituric acid(TBA) and xanthine oxidase methods respectively. In addition,the concentration of cardiac troponin I(cTnI) in the serum was detected by ELISA. Results:① The SOD activity and MDA concentration of CIH group were significantly higher than those of other groups(P < 0.05). The MDA concentration of NAC group was lower than that of control group(P < 0.01). ② The cTnI concentration of CIH and NAC groups was significantly higher than that of control group(P < 0.01). ③The degeneration of muscular tissues,transverse striation blurred,and fabric effusion were observed in tissue pathological section in CIH and NAC groups. However,normal tissue was found in control group. Conclusion:The cardiocytes were injuried by producing activation oxygen in OSAS animals,and this effect can be partially inhibited by NAC.