Recent studies on ferroelectric liquid crystals (FLCs) with an alkanoyl group are reviewed in this article. The FLCs exhibit large spontaneous polarization, especially when another chiral group is introduced at the opposite side of the core. The maximum value reaches 1130 nC/cm2, which is almost the same as the total transverse dipole in the molecule. Fastswitching FLC mixtures can be obtained by using these compounds. The synthesis and properties of FLC polymers having the same mesogen and chiral group are also described, and some applications of the FLC mixtures in devices for optical communication reported.