Electrically conducting polymers are promising for applications in polymer based charge storage devices and for membrane applications. Composing polypyrrole with polyimide improves mechanical properties of polypyrrole and affects the electrochemical properties of the composite. In this paper resistance to ion flow of pure polyimide and of the polypyrrole/polyimide composite were studied by electrochemical impedance spectroscopy, comparatively, as a function of applied potentials and of amount of polypyrrole. Electron scanning microscopy and surface mapping were used for surface characterization. Observed behavior was explained with electroactivity of the components of the composite. Conclusions about the effect of polypyrrole on the structure and resistance were made.