We focused on the optical properties of square array of subwavelength holes created within a titanium nitride (TiN) thin film. The TiN layer was placed on top of the dielectric layer as a surface plasmonic system originated from an intermetallic–dielectric arrangement. The finite-difference time-domain method was used via an Optiwave package to simulate periodic array of square and circular holes within the TiN layer. The effect of geometrical and material parameters such as periodic constant (a), size (S), shape of the holes, and the electric permittivity of the dielectric substrate has been investigated. An extraordinary optical transmission was observed in comparison with the nonhole system. It was shown that the wavelength of plasmonic modes, as a characteristic feature of the system, was affected by changing the periodic constant and electric permittivity. Meanwhile, changing the size as well as the shape of the holes did not affect the position of the peaks. These results are in agreement with the characteristic equation for plasmonic structure, which relates the surface plasmon wavelength (λsp) to the geometrical and material parameters of the system. The intensity of excited peaks was explained by distribution of the z-component of the electric field obtained from simulation, which illustrated the role of the surface plasmon polariton, localized surface plasmon resonance, and waveguide mode in tuning the optical behavior of the system. The results showed that TiN is a promising candidate for replacing metals in a plasmonic application with particular chemical and mechanical features.