Composite of metal and conducting polymer is expected for the electrical application by the use of their advantages. The purpose of this research was to reveal photo-electrochemical deposition behavior of metal, which is important to control the formation rate and the composite's structure obtained by simultaneous metal deposition and polymerization under the photo-irradiation. Cathodic polarization curves for silver deposition on polypyrrole film with different substrates under UV irradiation were compared in addition to the electrical resistance of the polypyrrole and the substrate. Morphology of silver deposition on polypyrrole was characterized by microscopic observation. The experimental results showed that photo introduction to polypyrrole upon silver deposition enhanced the deposition rate to 24 times at maximum.