Poly(m-phenylenebutadiynylene)s having a side chain with p-(4-pentylcyclohexyl)phenyl and cyanobiphenylyl mesogenic core were synthesized from corresponding m-diethynylbenzene by oxidative polycondensation with a Cu-amine catalyst under O-2. These polymers showed an enantiotropic nematic phase that was confirmed by polarizing optical microscopy and XRD. Uniaxial alignment of these polymers was carried out by a rubbing technique. Polarizing IR results of the aligned samples suggested that the main chain and the mesogenic side chain were aligned in parallel to the rubbing direction.