Abstract: One porous stainless steel-supported manganese dioxide thin film electrode,fabricated by electrochemical method was evaluated as a potential electrode for electrochemical capacitors.The porous stainless steel substrate electrode was obtained by mask electrolysis in the sodium chloride solution containing a lyotropic liquid crystalline phase of p-tert-alkylphenoxy poly(oxyethylene) ether(Triton X-100).Manganese dioxide film was electrodeposited on porous stainless steel substrate under a potentiostatic mode.Liquid crystalline phases were examined using XP-330C polarizing microscope at room temperature.The surface morphologies of the electrode were characterized by SEM.The capacity of manganese oxide film electrode was investigated by cycle voltammetry and constant-current charge-discharge method in potassium sulfate solutions.The results showed that stainless steel exhibited a highly porous surface morphology with an irregular pore size in a range of tens nanometer to hundreds nanometer after electrochemical erosion with liquid crystal mask.The deposited manganese oxide film consisted of spherical particles with an average size of 80~90 nm.The manganese oxide film electrode presents a specific capacitance of 400 F/g when the charge consumed is 0.4 C/cm² in electro deposition.The highest capacitance of 320×10^-3 F/cm² could be obtained by cycle voltammetry at a scan rate of 20 mV/s,corresponding to a specific capacitance of 200 F/g.The porous stainless steel-supported manganese dioxide electrode shows promising applications in electrochemical super capacitors.