Microbial fuel cells are bio-electrochemical devices which can transfer chemical energy of fuels(such as organic acid,glucide and others) through the bio-catalysis of microorganisms into electrical energy directly.Some kind of bacteria which delivers its respiratory electrons onto cell surface can be used to construct MFC.MFC researches focus on bacteria which can produce electricity,electrode materials and structure of MFC bioreactor.MFC will have an extensive application future in treatment of waste water and bio-remediation.