ABSTRACT: A new method of synthesis of poly(ester carbonate)s, based on the reaction of dihydroxy compounds with diphenyl dicarbonates containing ester groups was presented. The monomers utilized were diphenyl dicarbonates of cis/trans-1,4-cyclohexane dicarboxylate and of terephthalate units with butanediol or bisphenol A. The process consisted of a precondensation step under a stream of dry argon at atmospheric pressure with the elimination of phenol, followed by a melt polycondensation step at 225 or 250C under vacuum. The prepared polymers consisted of linear chains containing partial random sequence distribution of monomer residues n the backbone. The inherent viscosities of polymers were from 0.23 to 0.48 dL/g and their Tg values were in the range 29 to 134C. This method may open door to novel polycarbonates containing other organic functional groups.