In this work, nitrogen ions were implanted into an aluminum sample prior to magnetron sputtering for deposition of TiN films by selfdesigned multifunction ion implanter. An 80nm thick aluminum nitride (AlN) layer is observed by Auger Electron Spectrometer. We examine the effects of AlN layer on the surface mechanical properties of aluminum by nanoindentation. The effects of the AlN layer on the surface mechanical properties are evaluated. The hardness and elastic modulus of the TiN films on the two different substrates (N ionimplanted and unimplanted) are almost constant in the near surface region and decrease with increasing indentation depths. A reduced rate of decrease in the hardness and modulus is observed in the TiN/N+-implanted aluminum. From the results obtained by scratch test, the adhesion strength of TiN/N+-implanted aluminum is better than TiN/unimplanted sample.