Abstract: Hydroxyl polyester has great value in the process of preparing degradable plastics. We have synthesized the hydroxyl polyester by the ring-opening polymerization with the bisphenol A epoxy resin and sebacic acid as the raw materials, and the benzoic acid as polymerization inhibitor. The influences of species and consumption of catalysts on molecular weight and polydispersity of products were studied. It was found that, under the condition of 10% OMMT,the number-average molecular weight of product could reach 13 459 and the weight-average molecular weight was 132 596,while the polydispersity was only 9.85. It was an intercalated hydroxyl polyester/OMMT nanocomposite.