The photochemical control of spontaneous polarization (Ps) and the electrooptic properties of ferroelectric liquid crystals (FLCs) was studied. The photoisomerization of photochromic molecules (azobenzene and spiropyran derivatives) in FLCs caused the disorganization of the liquid crystalline phase with concomitant change in the interaction of FLC molecules and alignment layer and induced a reversible change in physical properties of the FLC. The rate and efficiency of the change in properties are discussed in connection with the structures of FLCs.