Liver failure remains a life-threatening syndrome. With the growing disparity between the numbers of suitable donor organs and patients waiting for transplantation，efforts have been made to optimize the allocation of organs，to find alternatives to cadaveric liver transplantation and to develop extracorporeal methods to support or replace the failing organ. An extracorporeal liver support system has to provide the main functions of the liver：detoxification，synthesis and regulation. The understanding that the critical issue of the clinical syndrome in liver failure is the accumulation of toxins not cleared by the failing liver led to the development of artificial filtration and adsorption devices(artificial liver support).