The attachment of low molecular weight beta -diketone compound to random copolyphenylhydrosilsesquioxane (abbr. as Ph-T) backbone gave rise to the formation of beta -diketone based side chain liquid crystalline copolyphenylsilsesquioxane (abbr. as Ph-DK). Its copper complexes (abbr. as Ph-DK-Cu) were prepared following a heterogeneous reaction procedure. The structures of the Ph-DK and their copper complexes were well characterized by IR, NMR and GPC. The DSC heating curves of the Ph-DK-Cu show three endothermic transitions. The first transitions are from crystalline state to liquid crystalline state (I), the second transitions are from liquid crystalline state (I) to liquid crystalline state (II), and the third transitions are from liquid crystalline state to the isotropic liquid. The Ph-DK-Cu are thermotropic liquid crystalline polymers. Their clearing temperature and mesophase range DeltaT are lower than those of the corresponding Cu-coordinated beta -diketone based copolymethylsilsesquioxane liquid crystalline polymers. The influence of the content of the Cu2+ on the Ph-DK-Cu has been discussed. The chen-deal incorporation of metal ion into polysilsesquioxane molecule can change the liquid crystal molecular arrangement and the transition temperature.