In this article, abrasion performance of commercial nylon 6 and nylon 6/montmorillonite (MMT) nanocomposites was Studied. The polymer nanocomposites showed poor abrasion resistance compared to the neat polymer. The wear loss increased linearly with clay concentration. Changes in Surface morphology, composition, and structure were investigated by scanning electron microscopy (SEM), Fourier transform infrared (FTIR)-attenuated total reflection spectroscopy, and X-ray photoelectron spectroscopy (XPS). SEM images showed that all the abraded surfaces contained fractured particles. However, the abraded nanocomposite surfaces had much deeper grooves compared to the homopolymer. FTIR results showed an increase in the amount of alpha crystals and a decrease in the amount Of gamma crystals on all the surfaces after abrasion. This was attributed to the strain-induced gamma to alpha crystal transformation. The largest amount of alpha crystals was formed in the abraded Surface of pure nylon 6, and the amount of alpha crystals formed decreased with increasing MMT content. XPS results showed an increase in the [Si]/[N] elemental ratio for all nanocomposites after abrasion, indicating an increase in the clay content of the surface. Abrasive wear mechanism is as follows: (1) tensile tearing is the dominant wear mechanism for all the samples; (2) the cutting mechanism becomes more important when MMT content increases; (3) the polymer matrix is easier to be removed than clay during the abrasion process; (4) in nylon 6/MMT systems, the poor abrasion resistance is attributed to defects at the clay-polymer interface, resulting in greater wear of the polymer matrix. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 3286-3293,2009