Titanium nitride (TiN) films with nanostructure were prepared at ambient temperature on a (111) silicon substrate by the filtered cathodic arc plasma (FCAP) technology with an in-plane S filter. The effects of deposition parameters on the grain size, texture and nano-hardness of the films were systematically investigated. The grain size was obtained through calculation using the Scherrer formula and observed by TEM. The results of X-ray diffraction and electon diffraction indicated that increasing either negative subs~ate bias or argon flow promoted the formation of (111) preferred orientation. High argon flow leads to biaxial texture. The micro-hardness of the TiN films as a function of grain size showed a behavior according to the Hall-Petch relation under high argon flow.