Aim: Oral inflammation becomes a risk factor of coronary artery disease (CHD). The aim of the present study was to collect the further evidences about the correlation between periodontal disease and coronary artery disease. Materials and methods: 19 CHD patients with periodontitis, 19 CHD patients without periodontitis, 21 periodontitis patients without CHD and 17 healthy individuals were included in the study. Clinical examinations including probing depth, attachment level, bleeding on probing, plaque index, sulfide levels and tooth mobility, were performed for six sites of each tooth. GCF was collected from all individuals, and blood samples were withdrawn on the time of GCF sampling. PAF levels in GCF and serum samples were investigated by Enzyme-Linked Immunosorbent Assay. Results: the PAF level in serum and GCF from all patients (including the three groups) was higher compared to healthy subjects. And no difference could be observed among the PAF level in serum of the three groups. No difference was observed between the PAF level in GCF of periodontitis patients with and without CHD. The PAF level in GCF from CHD patients without periodontitis was lower than the level from periodontitis, but significantly higher than the level from healthy controls. And the PAF levels in both serum and GCF of all patients had significantly positive correlations with all periodontal parameters including SUL. Conclusions: PAF may be an mediator in the initiation and progression of coronary artery disease or periodontitis, and contribute to the correlation between atherosclerosis and periodontal disease.Grand by NSF,Zhejiang Province,China. X205009