In this study, the oxidative polycondensation reactions of benzylidene-3-hydroxyaniline (B-3'-HA) with air. H2O2, and NaOCl were studied in an aqueous alkaline medium at 40-90 degreesC. Oligobenzylidene-3'-hydroxyaniline O-B-3'-HA) was characterized by H-1-NMR, C-13-NMR, FT-IR, UV-Vis, size exclusion chromatography (SEC), and elemental analysis. With NaOCl oxident, the conversion of B-3'-HA was 98.0% under optimum conditions such as [B-3'-HA](0) =[NaOCl](0) = [KOH](0) = 0.1015 mol/L at 50 degreesC for 5h. H2O2 was less active than O-2 and NaOCl. According to the SEC analysis, the number-average molecular weight (M-n), weight-average molecular weight (M-w), and polydisperisity index (PDI) values were found to be 2640g mol-1, 5130g mol-1, and 1.942 using NaOCl, and 1060g mol-1, 3179 g mol-1, and 1.615 using air, and 2370g mol-1, 4720g mol-1, and 1.990 using H2O2, respectively. Thermal analyses indicate that O-B-3'-HA is stable against thermo-oxidative decomposition.