The crystalline morphology of a thermotropic aromatic copolyester with flexible spacer has been studied by microscopy techniques. Spherulites morphology under polarizing microscope were observed for solution cast specimens. They were composed of radially growing crystalline lamellae of thickness around 10 nm. It was found that the molecular chains are oriented in the thickness direction . The influence of molecular chain rigidity on crystalline be-hayior of aromatic copolyester has also been studied. Results indicate that the crystallinity of materials increases with increasing the molecular chain rigidity.