The new linear thiopolyesterdiols (PEs) containing sulfur in the main chain were synthesized by melt polycondensation of newly obtained benzophenone-4,4'-bis(methylthioacetic acid) with excess of 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. All these PEs ((M) over bar(n) of 2000-2600) were converted to thiopoly(ester-urethane)s (PEUs) by polyaddition reaction with hexamethylene diisocyanate or 4,4'-diphenyl-methane diisocyanate, which was carried out in melt at the ratio of NCO/OH = 1. The resulting thermoplastic PEUs were amorphous and elastomeric, with elongation at break ranging from 630 to 1200%. The polymers were characterized by Fourier transform infrared, H-1 NMR, thermogravimetric analysis, differential scanning calorimetry, and in the case of PEUs, Shore A/D hardness and tensile properties.