The microstructure of TiN coatings and Ti1-xSixNy nanocomposite coatings was studied by means of x-ray diffrection, x-ray photoelection spectroscopy, high resolution transmission electron microscopy and atomic force microscopy. The results showed that the Ti1-xSixNy coatings consisted of TiN nanocrystallites with grain size of 3-5nm and amorphous Si3N4 phase. The roughness of Ti1-xSixNy coatings was less than that of TiN coatings prepared under the same conditions. The orientation of TiN crystals in the Ti1-xSixNy coatings was discussed on the basis of interface energy.