Nonlinear Electrochemical Impedance Spectroscopy (NLEIS) is an emerging technique that can be used to characterize an electrochemical system. In this technique, fundamental as well as higher harmonic frequency responses are recorded and analyzed directly to understand the system under investigation. The main objective of this thesis work is to establish a numerical framework to determine interfacial reaction mechanisms using NLEIS technique. This framework was validated by comparing the model predicted data with experimental data acquired by an in-house developed setup. Initially, a simple system (Au in Fe2+/Fe3+), which involves a single electron transfer reaction, is considered to establish the NLEIS framework, later it extended to analyse a more complex system such as Cu electro-deposition from the acidic sulfate solution. The extensive analysis of the data revealed that NLEIS method has the potential to identify mass transfer effects and system instabilities quickly, and has the potential to identify right mechanism at the electrode-electrolyte interface unambiguously. In this viva voce presentation, the following topics will be discussed in detail: NLEIS vs. linear EIS, methods to acquire experimental and numerical data, important findings from the analysis of results, and future scope.