The used method of tilt polarized beam allows determining the double refraction (DR) in thin films at different incidence angles and DR value enables to estimate the orientation effects and the orientation order. The method is for the first time applied to the substance in LC phase, on the interphase boundary. The results allowed not only the orientation order estimation but also the conclusion about supramolecular structure (domain) morphology - the domains form the stacks of disklike heptamer polycyclosiloxane (HPCS) molecules located mostly in parallel. Anisometric domains formed by HPCS molecules in their turn are aligned generally in parallel in respect to the compound thin layer surface.