Objective:To investigate the expression of CD4+ Foxp3+ regulatory T cells and different cytokines in peripheral blood of patients with coronary heart disease(CHD),and to explore the roles of them in CHD pathogenesis. Methods:21 patients with acute myocardial infarction(AMI),16 patients with unstable angina(UA),21 patients with stable angina(SA)were recruitde. The percentage of CD4+ Foxp3+ Treg of patients was measured by flow cytometry,and ELISA was used to analyze the blood plasma levels of cytokines(TNF-α,IL-10,IFN-γ,IL-4,TGF-β). Results:①The percentage of CD4+ Foxp3+ Treg decreased significantly in patients with acute coronary syndrome(ACS)compared with normal group(P < 0.001). ②Compared with SA patients,the level of TNF-α in AMI patients significantly increased(P < 0.05). In addition,the percentage of CD4+ Foxp3+ Treg in AMI patients was positively correlated with level of IL-10(P < 0.05). ③No correlation was found between CD4+ Foxp3+ Treg percentage and other cytokines(TNF-α,IFN-γ,IL-4,TGF-β)in CHD patients. ④There was no correlation between CD4+ Foxp3+ Treg and levels of total cholesterol,triglyceride,high or low density lipoprotein. Conclusion:The decreased percentage of CD4+ Foxp3+ Treg and increased TNF-α in peripheral blood of ACS patients may participate in ACS development and progression.