Objective To elucidate the clinical application value of intravascular ultrasound(IVUS) in assessing intermediate lesions and the relationship between serum levels of fractalkine,CD36 and LP-PLA2and severity of coronary artery atherosclerosis.Methods One hundred and twenty patients with unstable angina underwent coronary angiography.Then the patients were divided into two groups:severe lesion group (lumen diameter stenosis greater than 70％,including 40 patients),and the intermediate lesion group lumen diameter stenosis(50％～70％,80 patients).IVUS were performed in all patients to analysis the coronary lesions.Concentrations of CD36,fractalkine and LP-PLA2 were measured by means of ELISA.Results IVUS found that 74％ intermediate lesion patients had soft lipid plaques,while 48％ severe lesion patients had lipid plaques ( P＜0.01 ).Patients with severe lesion had larger plaque burden and vascular remodeling index than those of patients with intermediate lesions(P＜0.05～0.01).There were 59 patients(74％) in the intermediate lesion group underwent PCI.IVUS also found the PCI patients had larger plaque burden and vascular remodeling index.Concentration of CD36 was significantly higher in severe lesion group than that of intermediate lesion group (P＜0.05).Conclusions IVUS could further clarify the characteristics of the intermediate and severe lesions,and provide guidance for PCI treatment.Plasma CD36 level could be used to predict pathological severity of coronary atherosclerosis.