Electrochemical activity of poly-2,5-dimethoxyaniline (PDMAn) is similar to parent polyamline because of two symmetric substituted groups., Three oxidation states of PDMAn can transform reversibly, known as the completely reduced leucoemeraldine(L), intermediate emeraldine(E) and the fully oxidized pernigraniline(P). In voltammograms, the L/E, E/P transformation peaks are located at 0. 19 and 0. 51 V, respectively. Doping polymer and intrinsic polymer follow the redox transformation as L reversible arrow EH reversible arrow P and LH reversible arrow EH reversible arrow P separately. And E/P transformation peak shifts to lower potential by increasing pH value. In de-aerated solution the platinized polymer has an evidently catalytic activity on ISOpropanol oxidation. Furthermore the oxidative current enhances with increasing potential cycling numbers, whereas it decreases for platinized Pt electrode. The Pt particles not only highly disperse in PDMAn membrane, but also interact with PDMAn, resulting in changing their geometric structure and the electron properties of that metal. It is illustrated that as a catalytic system with a high catalytic and anti-poisoning activity, platinized PDMAn membrane electrode will also catalyze isopropanol oxidation in pH = 4. 7 buffer solution. It is pointed that PDMAn will degrade after preservation in air for three years.