Objective:To evaluate the clinical value with positron emission tomography/computerized tomography(PET/CT) imaging for the detection of vulnerable plaque in atherosclerotic lesions. Methods:Sixty people with a age of over 60[mean age (69.2±7.1)years] underwent three dimension(3D) whole-body fluorine-18-2-fluoro-2-deoxy-D-glucose(18F-FDG) PET/CT imaging and were evaluated retrospectively, including 6 cases assessed as normal and 54 cases with active atherosclerotic plaque. Fifty-four cases with SUVs and CT values in the aortic wall of high-FDG-uptake were measured retrospectively. These high-FDG-uptake cases in the aortic wall were divided into three groups according their CT value. Cases in group 1 had high uptake in atherosclerotic lesions of the aortic wall with CT value of less than 60 Hu(soft plaque). Cases in group 2 had high uptake with CT value between 60-100 Hu (intermediate plaque). Cases in group 3 had high uptake with CT value more than 100 Hu(calcified plaque). Group 4 was normal. Results: In group 1, there were 42 high-FDG-uptake sites (average SUV 1.553±0.486). In group 2, there were 30 high-FDG-uptake sites(average SUV 1.393±0.296). In group 3, there were 36 high-FDG-uptake sites(average SUV 1.354±0.189). In group 4, there were 33 normal-FDG-uptake sites (average SUV was 1.102±0.141). The SUVs showed significant difference among the four groups(F = 678.909, P = 0.000). There were also significant difference found between the normal-FDG-uptake group and the high-FDG-uptake groups(P = 0.000, 0.000, 0.001, respectively). Conclusion:Different degrees of 18F-FDG uptake in active large atherosclerotic plaque were shown in different stages of atherosclerotic plaque formation. The soft plaque had the highest FDG uptake in this study. This suggested that 18F-FDG PET/CT imaging may be of great potential value in early diagnosis and monitoring of vulnerable soft plaque in atherosclerotic lesions.