Thephotoelectrochemicalbehaviorofpolyaniline(PAn)filmwasstudiedinaqueouselectrolytesolutioncontainingFe(CN)63-/Fe(CN)+4-redoxcouple.ItwasfoundthatPAnfilmspossessthepropertiesofp-typesemiconducterandacathodicphotocurrentashighas700μA/cm2wasobservedwhenirradiatedunderpolychromaticlightof100mW/cm2.