Conformations of a single semiflexible polymer chain dissolved in a low molecular weight liquid crystalline solvent (nematogen) are examined by using a mean field theory. We takes into account a stiffness and partial orientational ordering of the polymer. As a result of an anisotropic coupling between the polymer and nematogen, we predict a discontinuous (or continuous) phase transition from a condensed‐rodlike conformation to a swollen‐one of the polymer chain, depending on the stiffness of the polymer. We also study a single polymer chain confined in a smectic phase. © 2004 American Institute of Physics