Aim To clarify the binding and degradative pathwa y of lipoprotein(a) and oxidized lipoprotein(a). Methods The binding and the competitive binding assays about Lp(a) and oxidized Lp(a) with the mouse peritoneal macrophage were performed. Results Lp(a) was bound with affinity, saturation to macro phage surface. LDL was minimal potency in competing with Lp(a) for the binding site, in contrast, ox LDL and ox Lp(a) were efficient competitor for the bindi ng of Lp(a). Oxidative modification of Lp(a) by Cu 2+ increased markedly i ts binding to macrophages. Ox Lp(a) and ox LDL were excellent competitor for the binding of ox Lp(a) to macrophages. Conclusions The binding of Lp(a) with macrophages by the scavenger receptor medi ated pathway; Scavenger receptor provided a significant route for the metabolism of ox Lp(a), perhaps, any other special receptor also mediated the binding of ox Lp(a) to macrophages.