A compound having a relatively low viscosity, a broad nematic phase temperature range, a good compatibility with other liquid crystal components at low temperatures and a positive large dielectric anisotropy value, and a liquid crystal composition having a low viscosity and capable of realizing a low driving threshold voltage of display elements are provided, which compound is a cyclohexane derivative expressed by the formula ##STR1## wherein R is 1-10C alkyl group, l is 1 or 2, m is 0 or 1 and l+m=2.