Poly(phenylbenzoate methylsiloxane)s with alkyl spacer groups of different length (4, 6, and 11 carbon atoms) were synthesized, studied, and compared with the corresponding low-molecular-mass compounds that model the side chains of macromolecules. The temperatures of phase transitions to the LC state were determined. It was shown that in a dilute solution under applied sinusoidal electric field, the polymers behave as flexible-chain polymers with each mesogenic unit oriented independently of the other units. In a mechanical shear field, the Maxwell constant changes its sign from positive in the monomer solution to negative for the polymer. This evidences that the entire macromolecule orients in the hydrodynamic field so that the main axes of mesogens are predominantly oriented normal to the axis of macromolecule.