As an in vivo indicator of vascular injuries, circulating endothelial cells (CECs) have been used as a marker of endothelial damage in a variety of vascular disorders. C-reactive protein (CRP) is a sensitive indicator of inflammation. To investigate the presence of CECs in patients with acute myocardial infarction (AMI) and to evaluate their clinical associations and possible relationship with infection, CECs from peripheral blood were isolated by using immunomagnetic beads coated with antibodies against CD146. Their endothelial origin was confirmed by the positive labeling of von Willebrand Factor (vWF), CD31 and electron microscope. Results showed that CECs number and CRP level were 52 (28-81.5) cell/ml, 7.98+/-2.25 mg/l and 10.5 (6-16.5) cell/ml, 1.41+/-2.05 mg/l in AMI patients (n=37) and health controls (n=42) respectively (p<0.001). The apoptosis rate and necrotic rate of CECs in AMI were 25% and 19%, respectively. Correlation analysis revealed a significant positive correlation between CECs and CRP (r=0.505, p=0.001). CECs numbers did not correlate with age, gender, serum cholesterol, hypertension, obesity, history of cardiovascular disease, or smoking. These results suggest a strong correlation between level of CRP and counts of CECs in patients with AMI. The number of CECs and CRP may be combined to reflecting the endothelial cell injury.