The influences of substrate surfaces on the formation behaviour of banded texture and its thermal stabilities have been studied for an aromatic X-shaped main-chain liquid crystalline polyester. The oriented polymer films prepared by shear on a glass substrate were found to exhibit a strong bounding effect, which was very effective in stabilizing or keeping the structural orders of oriented polymer chains, even for a long time in the mesomorphic state and also in stimulating the band formation process during cooling. Such an influence is considered to arise from strong interfacial interactions between the solid substrate and the mesomorphic polymer molecules deposited on it. Similar phenomena were also observed in the case of PET him adopted as substrate. However, they were quite different when the glass substrate was replaced by a Teflon sheet : the uniformity of polymer chain alignments on it was difficult to maintain even in a rapid cooling process after shear cessation, resulting in a formation of irregular banded texture. The melting-induced re-orientation behaviour of polymer chains was also examined for a drawn fibre.