Abstract: Effluent organic matter (EfOM) refers to the residual refractory organic materials in effluent after the primary and secondary biological treatment of sewage.The presence and characteristics of EfOM in wastewater are of great interest with respect to discharge quality and the efficiency of advanced treatment facilities.This paper summarized the characterization methods of EfOM including the molecular weight distribution,hydrophobic/hydrophilic fractionation,and excitation/emission matrix (EEM).The characteristic transformation of EfOM in the treatment processes has been summarized.At present,efficient and applicable advanced wastewater treatment processes including ozonation and membrane filtration.Nevertheless,there still needs urgent solution to reducing their operation costs.