AIM: To explore the possible changes in cell adhesion molecules and composition of complement activation in patients with acute myocardial infarction (AMI). METHODS: The expression of leukocyte CD18, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular-cell adhesion molecule-1 (sVCAM-1) and composition of complement activation (sC5b-9) concentrations of patients with AMI (67 cases), old myocardial infarction (OMI, 42 cases) and 38 healthy volunteers were measured using enzyme-linked immunosorbent assay(ELISA). RESULTS: The expression of leukocyte CD18, sICAM-1,sVCAM -1 and sC5b-9 were significantly higher in AMI patients than that in normal controls and OMI patients(P