In here, the facile synthesis and thermal characterization of a novel polyphenol containing Schiff base pendant group, poly(4-{[(4-hydroxyphenyl)imino]methyl}benzene-1,2,3-triol) [PHPIMB], are reported. UV-vis, FT-IR, 1H NMR, 13C NMR, GPC, TG/DTG-DTA, CV (cyclic voltammetry) and solid state conductivity measurements were utilized to characterize the obtained monomer and polymer. The spectral analyses results showed that PHPIMB was composed of polyphenol main chains containing Schiff base pendant side groups. Thermal properties of the polymer were investigated by thermogravimetric analyses under a nitrogen atmosphere. Five methods were used to study the thermal decomposition of PHPIMB at different heating rate and the results obtained by using all the kinetic methods were compared with each other. The thermal decomposition of PHPIMB was found to be a simple process composed of three stages. These investigated methods were those of Flynn-Wall-Ozawa (FWO), Tang, Kissinger-Akahira-Sunose (KAS), Friedman and Kissinger methods.