The structural and morphological evolution of mono-domains in thin films has been investigated for a series ofliquid crystalline (LC) copolyethers. The copolyethers studied were synthesized by the reaction of 1-(4-hydroxy-4’-biphenylyl)-2 -(4-hydroxyl-phenyl)propane (TPP) with 1, 7-dibromoheptane and 1, 11-undecane at different compositions(coTPPs-7/11). In contrast to the solution-cast thin films without annealing, which exhibit the isotropic homogeneousmolecular orientation, mono-domains with a homeotropic alignment were found in coTPP-7/11(5/5) after the thin films wereannealed in the high-temperature columnar phase (Φ′). Similar to the nucleation process in polymer crystallization,transmission electron microscopic observations show that small mono-domains appear in the initial stage of annealing, wheremolecules form a uniaxial in-plane chain orientation. With increasing annealing time, the molecular orientation graduallybecame tilted with respect to the substrate surface, and finally, a uniaxial homeotropic molecular orientation was achievedafter a prolonged annealing time. The lateral size of mono-domains was found to increase continuously with annealing timeand grew into a circular shape, indicating an isotropic lateral growth scheme which implies a hexagonal molecular packingproved by the electron diffraction experiments. The structural and morphological evolution of mono-domains in thin films has been investigated for a series of liquid crystalline (LC) copolyethers. The copolyethers studied were synthesized by the reaction of 1- (4-hydroxy-4’-biphenylyl) 4-hydroxyl-phenyl) propane (TPP) with 1, 7-dibromoheptane and 1, 11-undecane at different compositions (coTPPs- 7/11) orientation, mono-domains with a homeotropic alignment were found in coTPP-7/11 (5/5) after the thin films were annealed in the high-temperature columnar phase (Φ ’). Similar to the nucleation process in polymer crystallization, transmission electron microscopic observations show that small mono-domains appear in the initial stage of annealing, wheremolecules form a uniaxial in-plane chain orientation. With increasing annealing time, the molecular orientation graduallybecame tilted with respect to the substrate surface, and fi nally, a uniaxial homeotropic molecular orientation was achieved after a prolonged annealing time. The lateral size of mono-domains was found to increase continuously with annealing time and grew into a circular shape, indicating an isotropic lateral growth scheme which implies a hexagonal molecular packingproved by the electron diffraction experiments.