Abstract: A new aromatic polyester in which the methylene flexible spacers are connected with the rigid unit containing benzene rings was prepared by interfacial polycondensation: The polymer was characterized by the elemental analysis, IR spectroscopy, hot-stage polarized light microscopy, DSC, x-ray diffraction and small angle laser scattering techniques. The structure and properties of polyester obtained was investigated. The results showed that the polymer is a thermotropic liquid crystal and appeared of nematic and smectic texture. Thermal history of polymer had a significant effect on its thermal behavior. According to the results of differential scanning calorimetry of the polymer, liquid crystal transition peak was larger than crystallization peak in cooling run, which was suggested to arise from the supercooling. Furthermore, the thermal analysis of polyester revealed that clearing transition presented the characteristic of equilibrium process, so the entropy of this transition might offer some indication of the order present in the system.