Aim To observe the binding specificity of aptamers and THP-1 macrophage derived foam cells and atherosclerotic lesions.Methods The FITC-labeled PM1,binding to THP-1 macrophages,vascular smooth cells,endothelial cells and THP-1 macrophage derived foam cells were observed by fluorescence microscopy respectivly.Model of atherosclerosis was formed by high-fat feeding rabbit methods.The binding of aptamers and atherosclerotic lesions were detected by fluorescence microscopy and PCR.Results PM1 didn't bind to THP-1 macrophages,vascular smooth cells and endothelial cells but bind to THP-1 macrophage derived foam cells and atherosclerotic lesions.Conclusions we have obtained PM1 specifically binding to THP-1 macrophage derived foam cells and atherosclerotic lesions.