A study of Al/Al2O3/polyaniline interface in a corrosive medium has been reported. The system has been used to evolve an equivalent circuit model, based on electroanalytical measurements. The model evolved has been used to simulate interfacial parameters such as Cdl, Rct, Q, Rs for different experimental conditions, and these have been used to diagonise the nature and type of protective role the polyaniline coating offers. Synergization of experimentally observed parameters and simulated parameters from equivalent circuit models has been demonstrated as a protocol to evaluate the protective nature of polyaniline coating.