The property of surface electron in undoped IIn0.13Al0.87N epilayers with different thicknesses has been investigated using x-ray photoemission spectroscopy (XPS) and micro-Raman scattering spectra. XPS has been used to determine the characteristic of the native oxide at the free surfaces of In0.13Al0.87N film. It is showed that the binding energy shift to higher with the thickness reduction from the Al 2p, N 1s, In 3d5/2 spectra. While, there is more native oxide at the surface of In0.13Al0.87N film with the decrease of thickness. In addition, a broad peak in high energy region was only observed in the thinnest In0.13Al0.87N epilayer from micro-Raman results, and it may be relative to L+ coupled mode of In0.13Al0.87N.