In this article, 3-Hexyl thiophene (3HTh) monomer was electrocoated on carbon fiber micro electrode (CFME) to study electrochemical impedance spectroscopic (EIS) analysis. Poly(3HTh)/CFME is characterized by Cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), Scanning electron microscopy-Energy Dispersive X-ray analysis (SEM-EDX), and electrochemical impedance spectroscopy (EIS). The effects of different monomer concentrations (0.5, 1.0 and 1.5mM) on polymer were reported in 0.1M tetraethyl ammonium tetrafluoroborate (TEABF4)/acetonitrile (ACN) solution. The highest low frequency capacitance (C-LF = 1.394 mF cm(-2)) was obtained for [3HTh](0) = 0.5mM. The equivalent circuit model of R(QR(CR)(RW))(CR) was examined for polymer/electrolyte system.