A sulfur-bearing substituent, 2-thiazolidinethione, poly(organophosphazene) with side groups of this substituent and its metal polymer complex with cobalt(II) were synthesized and characterized. The structures of these compounds were investigated by means of IR, UV DTA, EA and H-1 NMR. The relationship between the structure and properties of poly(organophosphazene) was discussed. The results show that the poly(organophosphazene) with 2-thiazolidinethione has better thermal stability than the ligand investigated by TGA. Furthermore, the metal polymer complex showed an electroactivity due to the Co2+/CO3+ redox process confirmed by CV. (C) 2002 Elsevier Science. BN. All rights reserved.