To obtain a liquid crystalline polyester which can be easily prepared at a low industrial cost wherein liquid crystal orientation can be easily fixed and a small wavelength dispersion of birefringence is realized, and to prepare an optical film which can be formed into a homogeneous, large-area film wherein optical characteristics such as wavelength dispersion of birefringence can be precisely adjusted to desired values and orientation can be fixed at a desired state.

The liquid crystalline polyester comprises 1-50 mol% structural unit (a), 1-49 mol% structural unit (b), 1-49 mol% structural unit (c), 0-49 mol% structural unit (d) and 0-50 mol% structural unit (e). The optical film is obtained from the same.