A novel polymer (SDP) was first synthesized from 2,2'-diamino-4, 4'-bithiazole (DABT) with salicylic acid and paraformaldehyde (PF). SDP-Fe2+ was prepared from SDP and FeSO4 in DMSO. SDP-Prussian blue was prepared from SDP-Fe2+ and potassium ferricyanide (K-3[Fe(CN)(6)]) in DMSO. They were characterized through LR, H-1 NMR, XPS and ESR. The magnetic behavior of two polymeric complexes was measured as a function of magnetic field strength (0-60 kOe) at 5 K and as a function of temperature (5-300 K). SDP-Prussian blue exhibits a hysteresis cycle at 5 K, the observed coercive field is H-e = 40 Oe, and the remnant magnetization M-r= 0.035 emu g(-1). The result shows that SDP-Fe2+ is an antiferromagnet while SDP-Prussian blue is a ferromagnet. (C) 2001 Elsevier Science Ltd. All rights reserved.