Nano-films consisting of an alternating sequence of positively and negatively charged polyelectrolytes have been prepared by means of the electrostatic layer-by-layer sequential assembly technique on treated and untreated mild steel wires. The mild steel wires were pretreated electrochemically to modify the mild steel surface. The modification of the mild steel surface resulted in increasing the adhesion of the obtained nano films and prevented the corrosion attack during the coating processes. Different concentrations of 2-phosphonobutane-1,2,4-tricarboxilic acid and Benzotriazole inhibitors were encapsulated between cationic and anionic polyelectrolytes nano films. The encapsulation of benzotriazoe in the deposited nano films was verified by U.V visible spectroscopy. The thesis mainly focuses on the effect of these nano-films of polyelectrolytes with different functional groups on the corrosion protection. Tafel, corrosion potential, potentiostatic and Ecorr vs. time experiments were carried out in 0.7M NaCl solution. Weight loss method was used for measuring the corrosion rate of coated and uncoated mild steel substrate. A significant improvement in the corrosion protection was achieved especially in the case of electrochemically modifying the mild steel surface and encapsulating the inhibitors between the polyelectrolyts nano films. The atomic force microscopy AFM was used for monitoring the surface morphology of the obtainednano films.