Abstract: The Oliver method and Pharr method were employed to calculate the elastic modulus and the stiffness of titanium nitride (TiN) films based on nanoindentation experiment. With the help of finite element analysis software DEFORM, the yield strength of the TiN film were determined through dimensional analysis and curve fitting. The mechanical property analysis at seven feature points were carried out for the films with different thicknesses using FEM, and the result was verified by a separation experiment of film and substrate. The results show that the stress at the pressure point P0 exhibited the maximum value of 4 230 MPa. The stress concentration appeared at pressure point Ps, the joint between film and substrate, in which tangential stress reached to the maximum from 3 150 MPa to 2 260 MPa with the increase of film thickness from 1 μm to 2.5 μm. And the place around the point Ps was easiest to peel off, which was proven by the seperation experiment. The influence of substrate on the film declined with the increase of film thickness.