Abstract: Objective To observe the serum level changes of high-sensitivity C-reactive protein in every group patients with Coronary artery disease (CAD), to observe the conrrelation between atherosclerotic plaque and serum levels of hs-CRP and to explore the role of hs-CRP in pathogenesy and therapy. Methods One hundred and four patients ( male 66, female 38 ) with CAD were enrolled in this study. These patients included stable angina (SA) (28), unstable angina (UA) (54) and acute myocardium infarction(22). All patients underwent coronary angiography. Intravascular ultrasound (IVUS) was performed in single-artery lesion patients. In addition, 20 patients with normal CAG served as control. Serum hs-CRP level of all patients was measured by emulsion reinforced immunoturbidimetry (ITM). Results Serum levels of hs-CRP are statistically different in AMI, UA, SA and NS groups (P<0.01). Serum levels of hs-CRP were statistically higher in soft plaque group than those in fibrous plaque group and calcified plaque group (P<0.01). In fibrous plaque group, serum levels of hs-CRP were significantly higher than those in calcified plaque group respectively. Conclusions hs-CRP plays an important role in the development of CAD and can be considered as a predict factor in the diagnosis of CAD. Serum levels of hs-CRP is related to some plaque characters such as eccentricity and vulnerability.