The　laboratory-scale　experiments　were　conducted　to　investigate　treatment　performance　of　MBR-NF　concentrate　of　landfill　leachate　by　Fenton　process.　The　affecting　factors　of　dosage　of　FeSO4·7H2O,　H2O2/　Fe2+　ratio　(molar　basis)　and　initial　pH　value　on　removal　efficency　were　optimised.　Meanwhile,　the　changes　of　compositions　of　fulvic　acid　(FA)　and　hydrophilic　organic　matter　(HyI)　fractions　in　the　concentrate　during　Fenton　process　were　discussed　under　the　optimal　conditions.　The　results　showed　that　the　optimal　operating　conditions　were　as　follows:　FeSO4·7H2O　dosage　of　0.055　mol/L,　n(H2O2)/n(Fe2+)　ratio　of　4　and　initial　pH　of　7.58.　Under　these　conditions,　the　removal　efficencies　of　COD,　UV254,　and　CN　reached　79.6%,　93.7%　and　97.8%,　respectively.　During　Fenton　process,　the　organic　composition　of　the　concentrate　varied　significantly.　The　content　of　humic　substances　(HS)　decreased,　and　the　HyI　fraction　shifted　the　dominating　composition　of　dissolved　organic　matter.　The　UV　spectra　demonstrated　that　Fenton　oxidation　had　a　high　removal　efficency　for　FA,　while　less　effective　for　HyI.　Fourier-transform　infrared　spectra　exhibited　the　significant　changes　of　FA　structure,　while　few　in　HyI.