An oligomeric supramolecule of 1,5-diaminoanthraquinone (DAAQ), having a crystalline structure by pi-pi interaction, has been proposed as an active material for electrochemical capacitors. By choosing carefully the electro-oxidation conditions, an electroactive supramolecular DAAQ oligomer was obtained as a film, exhibiting a charge density of 50 Ah kg(-1). The oligomeric DAAQ film maintained its crystalline structure and showed reproducible redox responses over 20,000 cycles with little capacity loss (5%). Such a good reproducibility of the crystalline DAAQ oligomer was caused by isotropic and small conformational changes during the redox reactions.