Corrosion properties of CP-Ti and Ti-5%TiN composites produced through selective laser melting (SLM) in an artificial simulated body fluid (Hank''s solution) were investigated by using potentiodynamic polarization curves and electrochemical impedance spectra. The results demonstrate that SLM-produced CP-Ti primarily comprises the acicular α-Ti phase. The addition of TiN particles can bond well with the titanium matrix and refine the α-Ti grains, resulting in more grain boundaries. An SLM-produced Ti-5%TiN sample possesses better corrosion resistance than an SLM-produced CP-Ti sample in Hank''s solution because the tiny TiN particles, which act as micro-cathodes, are uniformly distributed in the titanium matrix. This accelerates the anodic dissolution process of the titanium matrix and allows the Ti-5%TiN composite to first enter the passivation state.