Aim To probe the relationship between plaque stability and expression levels of interleukin-6(IL-6),interleukin-18(IL-18)and tumor necrosis factor-α(TNF-α)in human coronary atherosclerosis.And to investigate the correlation of IL-6,IL-18 and TNF-α.Methods One hundred and four autopsy samples of coronary paraffin sections were selected and divided into unstable plaque group,stable plaque group and normal coronary group by means of SmartScape biology miscroscope analysis system.Plaque area,lipid core area and fibrous cap thickness in the three groups were measured and analyzed.The expression levels of IL-6,IL-18 and TNF-α in plaque of human coronary atherosclerosis were measured by immunohistochemical technique.Results There was no statistically and significant difference between the unstable plaque group and the stable plaque group in the area of coronary atherosclerosis plaque(P>0.05),but the lipid core area and fibrous cap thickness were statistically and significanly different between them(P<0.05).IL-6,IL-18 were not expressed,and TNF-α was little or not expressed in the normal coronary group.The expression levels of IL-6,IL-18 and TNF-α were higher in the unstable plaque group than in the stable plaque group,especially in the shoulder of fibrous cap and lipid core(P<0.01).There was positive correlation among the expression of IL-6,IL-18 and TNF-α.Conclusions The expression levels of IL-6,IL-18 and TNF-α in plague of human coronary atherosclerosis was not only related to plaque stability but also correlated among one another.