[en] Titanium and its alloys biomaterials have become relatively popular for surgical implants. Plasma nitriding are commonly used for orthopaedic and dental implants which are subjected to articulation, corrosion and wear, to increase the surface hardness, corrosion resistance and reduce the generation of wear debris. This paper aims to demonstrate the electrochemical behavior of plasma nitrided cp ti, A Commercially pure titanium cp was surface modified using Dc glow discharge plasma nitriding in order to study its microstructural changes in the modified surfaces that can improve the corrosion resistance of titanium. Dc glow discharge plasma nitriding was performed for different period of time (namely 5, 10, 15, 20,25 and 30 hours). The glow discharge was occurred by applying 650 V between the two parallel electrodes under 3 mbar nitrogen gas pressure. To characterize the nature of the modified layers produced and to correlate with the corrosion behavior of these medical materials, Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) was employed on the modified surface. The effect of sputtering process that can accrue during the nitriding process on the surface roughness was studied using Atomic Force Micros (AFM). EIS studies in Buffer Phosphate Solution (BPS) have been carried out in order to understand the corrosion and passivation kinetics after plasma nitriding. The results shows that as the nitriding time processed the N⁺ concentration increases comparing to the metal and alloy matrix elements. The AFM results show that the nitriding process leads to reduce the surface roughness. The electrochemical impedance tests were carried out at open circuit potential before and after polarization. All the plasma nitride specimens show electrical impedance spectra a purely capacitive behavior characteristic of thin films. (Author)