The process of leukocyte adhesion was mediated by the intercellular adhesion molecular. In this study, both the influence of burn serum on the expression of PMN CD11b/CD18 and the role of CD11b/CD18 on the burn serum stimulated PMN adhesion to endothelial cells (EC) were investigated. The expression of CD11b/CD18 on PMN incubated with burn serum for 2 hours was increased obviously. So was PMN adhesion to EC. Monoclone antibody to PMN CD11b/CD18 could reduce the normal PMN adhesion to EC by half and block the increasing PMN adhesion induced by burn serum. These indicated that PMN CD11b/CD18 may be the main adhesion molecular participating in the increasing PMN adhesion to EC due to severe burn.