A novel liquid-crystalline polymer (LCP) containing an azobenzene group directly connected to a tolane moiety (azotolane moiety) was synthesized. The LCP showed a nematic phase in a broad temperature range (>200 degrees C). Trans-cis photoisoinerization and cis-trans thermal isonterization occurred even though the LCP contains a long azotolane moiety. The homogeneously aligned film of the LCP exhibited an. extremely large value of Delta n (0. 70 at 633 nm). Upon irradiation with a pumping beam in the LC phase, a large change in An was induced due to destruction of the homogeneous alignment of the azotolane moieties.