The abrasive wear of pure ultrahigh molecular weight polyethylene (UHMWPE) as well as one filled with nano- and microparticles (fibers) were investigated. It was found that abrasive wear resistance of microcomposites (containing AlO(OH) and Al2O3 microparticles) 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 (AlO(OH) and carbon nanofibers (CNF) as well as SiO2 and Cu nanoparticles) as opposed to microfillers can improve abrasive wear resistance of UHMWPE in a significantly less degree (up to 50%). Abrasive wear resistance of nanocomposites weakly depends on the type of filler and is defined by the polymeric matrix (permolecular) 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.