The aged-refuse-based reactor, which has high efficiency in treating landfill leachate by microbial degradation,adsorption, ion exchange and chelating of aged refuse particles,received a wide range of attention and application.Anammox(anaerobic ammonium oxidation) bacteria, which has the unique metabolic ability to combine ammonium as electron donor and nitrite as electron acceptor to form nitrogen gas, plays an important role on the process of nitrogen reducing in landfill leachate treatment.