The abrasive wear of pure ultra-high molecular weight polyethylene (UHMWPE) as well as one filled with nanoand micro-particles (fibers) was investigated. It was found that abrasive wear resistance of micro-composites (containing AIO(OH) and Al2O3 micro-particles) can grow up by 16-18 times in comparison with pure UHMWPE depending on the strength and size of the filler as well as abrasive grit. Nanofillers (AIO(OH) and carbon nanofibers (CNF) as well as SiO2 and Cu nanoparticles) as opposed to micro-fillers can improve abrasive wear resistance of UHMWPE in a significantly less degree (up to 50 percent). Abrasive wear resistance ofnanocomposites weakly depends on the type of filler and is defined by the polymeric matrix (per-molecular) and counter-face abrasive grit. The comparative analysis of the wear mechanisms of UHMWPE based micro- and nanocomposites under abrasive wear (fixed abrasive particles) and dry sliding friction is carried out.