Abstract Novel ester acetal polymers were synthesized by the polymerization reaction of aromatic dicarboxylic acids with 1,4-cyclohexanedimethanol divinyl ether in organic solvent under heating. The obtained polymers show good solubilities in common organic solvents and high thermal stability. The number-average molecular weights of the ester acetal polymers range from 5000 to 7000 with M _w /M _n of 2.0‐3.0. The polymers can undergo acidolytic reaction rapidly at room temperature or at a slightly higher temperature. By making use of the high acidolytic activity of the ester acetal polymers, new imaging materials can be developed for thermal sensitive plates in computer-to-plate (CTP) and UV-CTP applications.