Objective To investigate the impact of chronic intermittent hypoxia (CIH) on cardiac function, and explore the role of NF-κB in the mechanisms of cardiac dysfunction due to CIH. Methods Twenty-four adult male Sprague-Dawley rats (body mass about 200g) were randomly divided into three groups: normal control(NC) group, CIH group and CIH＋proline dithiocarbamate(PDTC) group. The rats in CIH group were exposed to intermittent hypoxia (O2 5%～7%), 8 hours daily, totally 5 weeks. The rats in CIH＋PDTC group were raised under the condition similar to CIH group except intraperitoneal injection of PDTC [100mg/(kg?d)]. At the end of the exposure, body mass, blood pressure and heart rate of the animals were measured. Left global function was assessed by echocardiography. Nucleoprotein NF-κB level was detected by Western blot. Results At 5 weeks, the body mass of rats in CIH and CIH＋PDTC groups was lower than that in NC group. Compared to NC group, animals in CIH and CIH＋PDTC groups demonstrated an elevation in blood pressure [ (136.3±6.8) and (134.3±6.7) vs (122.3±4.1) mmHg, P＜0.001]; while the blood pressure was not significantly different between CIH and CIH＋PDTC groups. Left ventricular ejection fraction(LVEF) was lower in CIH group than in NC group [(73.0±5.6) % vs (86.0±4.3) %, P＜0.001], and higher in CIH＋PDTC group than in CIH group [(84.0±4.1) % vs (73.0±5.6) %, P＜0.001]. However, it was not significantly different between NC and CIH＋PDTC groups (P=0.117). There was no significant difference in heart rate among the groups. Compared to NC and CIH＋PDTC groups, the expression of NF-κB increased in CIH group (P＜0.001). However, there was no difference between NC and CIH＋PDTC groups. Conclusion Chronic intermittent hypoxia may impair left ventricular function of rats and NF-κB may be involved in the mechanisms.