The sputter coatings provide new approaches to the functionalization of textile materials. One of the key issues in the use of sputter coatings onto textiles is the interfacial adhesion between the coated layer and the fiber substrate. The interfacial bonding between polypropylene (PP) fibrous substrate and sputter coated copper was investigated and discussed by abrasion test and peel-off test in this study. It was found that the plasma pretreatment and heating during the sputter coating process obviously improved the adhesion of the coating layer to the PP fibrous substrate. The mechanism of the interfacial adhesion between copper and PP substrate was also examined by atomic force microscopy. The AFM observations revealed the surface and interfacial structures of the PP fibers.