The polymer of 4-[1-(4-hydroxyphenyl)ethylideneamino]phenol (4-HPEAP) being a Schiff base substitute was formed with use of oxidants such as air O(2), H(2)O(2) or NaOCl in an aqueous alkaline medium. The yield of polymer was found to be 95, 51 and 96 % for air O(2), H(2)O(2) and NaOCl, respectively. During these polymerization reactions of 4-HPEAP, H(2)O(2) demonstrated lower activity than NaOCl and air O(2). The spectral analyses results such as (1)H NMR and (13)C NMR showed that the phenol units were connected at ortho positions, forming the C-C coupling system. The polymer was found to show relatively high thermal stability. This polymer lost half of the weight at 230 degrees C. The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and electrochemical energy gaps (E'(g)) of 4-HPEAP and P-4-HPEAP were found to be -6.30, -6.15; -2.41, -2.57; 3.89 and 3.58 eV, respectively. According to UV-Vis measurements, the optical band gaps (E(g)) of 4-HPEAP and P-4-HPEAP were found to be 3.56 and 3.47 eV, respectively.