Abstarct: 4-iodobenzoic acid was refluxed with thionyl chloride the residue was filtered off, dried to give 4-iodobenzoyle chloride. The resulted compound reacted with sodiumazide dissolved in acetone and water, the solid was filterd off, dried to give white powder. 4-iodobenzoyl azide was refluxed in tolouen then react with Ethylhydrazinecarboxilate the powder of 1-ethoxy carbonyl-4-(4-iodophenyl)semicarbazide was filtered off. 1-Ethoxycarbonyl-4-(4-iodophenyl)semicarbazide and a water solution of potassium hydroxide were added for neutralization, then 4-(4-iodophenyl)-1,2,4-triazolidine-3,5-dion precipitated as powder the structure of this compound was confirmed using infrared spectroscopy. 1,2-bis (2-hydroxy ethyl) 4-(4-iodo phenyl)-1,2,4-triazolidin-3,5-dion was prepared via the reaction of 2-bromo ethanol with on mole urazole in DMF. The structure of the monomer were identified a confirmed by IR, 1H-NMR and 13C-NMR spectroscopies. Polymerization of the monomer with stoichiometric amount of various diisocyanates, hexamethylene diisocyanate (HMDI), tolylene diisocyanate (TDI), and isophorane diisocyanate (IPDI), led to new polymers, in high yields and inherent viscosities. These polymers was characterized by using and 1H-NMR spectroscopies, viscometery and thermal gravimetric analysis (TGA, DTG).