Abstract: By incorporating at least one of p-n-alkylcyanobenzene, p-cyanobenzylideneaniline and p-cyanophenyl p'-n-octyloxybenzoate into a Schiff base type nematic liquid crystal composition having negative dielectric anisotropy, a nematic liquid crystal composition having positive dielectric anisotropy is obtained. The nematic liquid crystal composition of the latter exhibits a liquid crystal state in a broad temperature range including room temperature and is useful for a torsion effect type electrooptical display device which can operate at low voltages.