Objective:To examine the effects of chronic intermittent hypoxia(CIH)on the NF-κB,IL-6 and PGE2 level in rats with periodontitis.Methods:32 male SD rats(6 weeks old)were randomly divided into 4 groups(n =8),group A(normoxic control),B (normoxic periodontitis),C(CIH)and D(periodontitis +CIH).Periodontitis model was established in the upper second molars by liga-tion technique and high-glucose diet in the rats of group B and D.The rats in the group C and D were subjected to CIH in a cycle of al-ternative nitrogen and oxygen in a closed chamber.The chamber was filled with nadir and zenith ambient oxygen every 1 20 seconds per cycle for 8 hours per day.The rats were sacrificed and the gingival tissues were examined for the detection of IL-6 and PGE2 expression by ELISA,and NF-κB expression by immunohistochemistry.Results:Histology revealed apical migration of junctional epithetlium and crestal alveolar bone resorption in group B and D,and in the above phenomena of group D was the severest.The content of NF-κB,IL-6 and PGE2 in group B,C,D was higher than that in group A(P <0.05),and in group D was the highest(P <0.05).Conclusion:Chro-nic intermittent hypoxia can aggravate the inflammation of periodontitis.