The electrochemical polymerization of azure A has been carried out using repeated potential cycling. The scan potential is set between -0.2 and 1.3 V (vs. Ag/AgCl). The electrolytic solution consisted of 5 mmol dm(-3) azure A and 0.5 mol dm(-3) Na2SO4 with pH 6.0. The temperature for polymerization was controlled at 50degreesC. An anodic peak and a cathodic peak appear at 0.38 and 0.23 V, respectively, on the cyclic voltammogram of poly(azure A) in 0.5 mol dm(-3) Na2SO4 solution of pH 1.0. Their peak potentials shift toward the negative direction as pH value increases from 1.0 to 4.0. Poly(azure A) has good electrochemical activity and stability in the aqueous solution at the above pH range. The UV-visible spectrum and FTIR spectrum of poly(azure A) are different from those of azure A. The FTIR spectrum of poly(azure A) indicates that no anions were doped into the oxidation form of poly(azure A). (C) 2003 Wiley Periodicals, Inc.