Two different series of new aromatic liquid crystalline (LC) polyesters were prepared from 3-phenyl-4,4'-biphenyldicarboxylic acid (PBDA) and 1-phenyl-2,6-naphthalenedicarboxylic acid (PNDA). PBDA and PNDA were polymerized with various aromatic diols such as hydroquinone, substituted hydroquinones, isomeric naphthalenediols and 4,4'-biphenol, and the resulting polyesters were characterized by DSC, WAXD, and on a cross-polarizing microscope for the study of their thermal transition and crystallization properties, and mesophases formed therefrom.