For the first time, the complex charge transport mechanism for polyprrole/poly(polystyrenesulfonate) (PPy/PSS) films in aqueous electrolyte solutions has been revealed by employing the cyclic/step electrochemical quartz crystal microbalance (EQCM) technique and the electrochemical/electrogravimetric impedance technique. Especially from the impedance experiments. the relative diffusion coefficient of charge transport has been obtained, and also the ion transport behavior in the slow charge transport process has been revealed. In PPy/PSS films. anion transport is considerable in the slow charge transport process, while cation transport is dominant in the fast charge transport process, It is shown that the presence of the slow charge transport processes is due to a slow electron transport process, not a slow ion transport process.