Abstract: The present invention relates to novel compounds, viz. poly(arylate-sulphones) and to a method of preparing same. The compounds according to the present invention have the following formula: ##STR1## WHEREIN R is a carbon-to-carbon bond in para- or meta-position; ##STR2## n, m are indices denoting statistical distribution of structures over the macrochain; n and m are statistical values ranging from 1 to 10; x is a statistical value ranging from 1 to 100; y = 3 to 20; z = 5 to 20.The method of preparing said poly-(arylate-sulphones) comprises polycondensation of dichloroanhydrides of dicarboxylic acids with a mixture of bisphenol of the formula: ##STR3## and an oligosulphone of the formula: ##STR4## wherein y = 3 to 20; ##STR5## said oligosulphone being contained in the mixture in an amount ranging from 3 to 97% by weight as calculated for the desired poly(arylate-sulphone). The reaction is conducted in a medium of chlorinated hydrocarbons, followed by isolation of the desired product.