The crystal structure of the compound 5-p-(trans-4-pentacyclohexyl) phenoxy-l-pentyne (PCH503A) was determined by X-ray diffraction. The structure and orientational behavior of the polymer (PPCH503A), prepared from the monomer compound, was examined. As a result, it was found that the polymers form an alternating comblike conformation of side chains and are: stacked into a smectic hexagonal structure. When shear stress was applied to the polymers, polymeric chains were oriented with their axes of mesogenic groups parallel to the shearing direction; that is, the polymer backbones were aligned perpendicular to the shearing direction. The oriented polymer exhibited a high anisotropy of electroconductivity, i.e., sigma(\\) (the electroconductivity parallel to the backbone) became 1.7 x 10(-5) S/cm upon doping iodine, and the ratio of sigma(\\) to sigma(perpendicular to) (the electroconductivity perpendicular to the backbone) was about 10.