Pretilt angles of various nematic liquid crystals (NLCs) aligned on the cured organic solvent soluble polyimide alignment film containing fluorine atoms have been measured. The relationship between obtained pretilt angles and physical properties of NLCs shows that the pretilt angle of NLCs increases linearly with the perpendicular component of permittivity of NLCs. This phenomenon suggests that the lateral substituents in NLC affects the generation of pretilt angles by the anisotropic-excluded-volume effect.