Three novel bithiazole-containing polymers were synthesized from 2,2'-diamino-4, 4'-bithiazole (DABT) condensed with bismaleimide, bis(methyloxycarbonyl ethyl)tin dichloride (BETD), and 4,4'-diphenylmethane diisocyanate (DPDI), respectively. A new series of polymeric complexes were prepared from Fe2+ and the three polymers. These polymers and their complexes were characterized through FTIR, H-1-NMR, and related techniques. The chemical compositions of the complexes were determined by XPS. The presence of the exchange interaction between the unpaired electrons was investigated by ESR spectroscopy. The magnetic behavior of these complexes was measured as a function of the magnetic field strength (0-40 kOe) at 5 K and as a function of temperature (5-300 K) at a magnetic field strength of 30 kOe.