The surface physical and chemical effects of abrasive erosion of polyurethane in three different fluids (H2O, polyacrylamide and NaOH) containing quartz particles have been investigated respectively. The surface profiles, elements constitutions, binding energies and functional groups of polyurethane surfaces before and after abrasive eroding have been analyzed with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectrometer (FT-IR). The surface physical effects of the abrasive erosion process were found to be microcutting, high-cycle fatigue and plastic fracture. The surface chemical effects turned out to be mechanical rupture of macromolecular chains, thermal decomposition of the allophanate groups and the biuret groups, hydrolysis of carbamate groups, and surface oxidative degradation.