A novel Schiff base type polyester containing 2,2′-diamino-4, 4′-bithiazole (DABT) was prepared by low-temperature interface polycondensation of 1,4-benzenedicarbonyl dichloride with 4,4′-(4, 4′-bithiazole-2,2′-diylbis(imine-2,1-diyl) diphenol (BDDP), which is derived from a 2,2′-diamino-4,4′-bithiazole (DABT) Schiff base reacted with a 4-hydroxybenzaldehyde monomer. The newly generated polyester was characterized by FTIR spectroscopy, elemental analysis, and X-ray diffraction spectroscopy. The thermal decomposition was investigated in nitrogen atmosphere using thermogravimetric analysis. The activation energies of the decomposition step of the polyester were calculated through the isoconversional methods of Kissinger-Akahira-Sunose (K-A-S) and the iterative equation. In order to estimate the reaction model that best describes the experimental data, the use of an empirical kinetic equation based on that proposed by Sestak-Berggren was investigated here. On the basis of the kinetic data, the life time estimates for the polyester generated from the weight loss of 5%, 10%, and 15% were also constructed.