Ferroelectrics are important industrial materials which are widely used for electronic applications such as nonvolatile memories, piezoelectric elements, actuators, insulating films for field effect transistors. Material design and synthesis of low-molecular-weight organic ferroelectrics, though unexplored field in comparison with inorganic or polymer ferroelectrics, have been desired to realize these excellent functions flexibly in lightweight materials. Recently, we have achieved completely new approach to ferroelectricity using molecular compound, in which 2 species of π-electron molecules are bounded by hydrogen bonds. The present ferroelectrics possess outstanding properties; spontaneous polarization which can be reversed in a low field approximately 1/100 of that required for polymers and huge permittivity reaching as much as 2,000-3,000.