A series of novel liquid crystalline compounds with a tetrahydropyrane ring were synthesized, and the physical properties have been measured. The compounds showed peculiar dependency of the dielectric anisotropy value on the connecting position of the tetrahydropyrane ring. This positional dependency is discussed with the measurement of the temperature dependency of the dielectric Constants, and the semi empirical quantum calculation. In accordance with the experimental result, it was found that the difference of the dielectric anisotropy value is influenced by the difference of the dipole moment value and the direction of the dipole at the most stable conformation.