The cyclic electrochemical quartz crystal microbalance (EQCM) technique and the electrochemical/electrogravimetric impedance technique have been used to reveal the ion transport mechanism of polypyrrole/nitrate (PPy/NO3) films in the slow as well as fast charge transport processes in aqueous electrolyte solutions. The relative contributions and the relative apparent diffusion coefficients of three ions in bath the slow and the fast charge transport process were obtained by assuming that the diffusion coefficients of two anions are similar, though three kinds of ions (anion and cation of an electrolyte, and another ion) rake part in ion transport. It is shown that cation transport is considerable in the slow charge transport process while anion transport is dominant in the fast charge transport process.