Electroactive polyaniline was prepared in various nonaqueous electrolytes, such as propylene carbonate (PC), gamma-butyrolactone (GBL), and acetonitrile (MeCN) containing aniline tetrafluoroborate (ATFB), by galvanostatic polymerization of aniline at 0.1 or 0.01 mA cm(-2). From the FTIR spectra, the molecular structures of the polyanilines prepared in the various electrolytes were similar to each other. Their morphologies were observed in SEM photographs. Discharge and charge tests were carried out to estimate their capacities and electrochemical behavior. Polyanilines prepared in the various nonaqueous electrolytes in this study had enough electroactivity to be utilized as cathode materials for rechargeable nonaqueous batteries. Polyaniline prepared in MeCN containing 1.0 mol dm(-3) ATFB at 0.01 mA cm(-2) especially was applicable as a cathode for battery use because of the large discharge capacity and the small effect of kinetics. The Walden product for each electrolyte solution, an index of the degree of dissociation of ATFB, was evaluated from the viscosity and conductivity measurements. The Walden product of MeCN containing 1.0 mol dm(-3) ATFB was smaller than that of PC, or GEL solution. It seems that the degree of dissociation of ATFB in various electrolytes for the electropolymerization would influence the discharge and charge characteristics of polyaniline.