Si3N4-TiN nano-composite has been prepared by an in situ compositing method with silicon nitride powder, aluminium iso-propoxide and titanium butoxide as the raw materials. The densification mechanism during hot-pressing and the microstructure of the densified materials were characterized from the point of view of phase composition, TiN inclusion distribution and the interface properties. The dense materials were mainly composed of beta’-sialons, residual alpha-Si3N4, silicon oxynitride, and TiN. The materials were featured by the very fine size of the precursor-derived particulate TiN which was homogeneously distributed in the matrix.