Abstract: The 21century is an era of high technology with information-based economy and digitized information. The explosive increase of information and the miniaturization of electronic devices demand new recording technologies and materials that combine high density, fast response, long retention time and re-writing capability. Ultrahigh density data storage at the nanometer/molecular-scale based on electrical bistability has attracted great attention in recent years. The latest progress in this field is reviewed from the viewpoint of recording material and technology. Future research and development of ultrahigh density data storage is also discussed.