Ultrafiltration　is　increasingly　used　in　fields　of　water　treatment　and　bio-energy　for　algae　removal　and　algae　harvest,　respectively,　but　membrane　fouling　caused　by　extracellular　organic　matter　is　still　a　challenge.　In　this　work,　oxidation-enhanced　ferric　coagulation　was　assessed　for　alleviating　membrane　fouling　by　extracellular　organic　matter　with　Fe(II)/permanganate　and　Fe(II)/persulfate　compared.　Characterization　of　extracellular　organic　matter　was　performed　before　and　after　pretreatments　to　evaluate　changes　in　molecular-weight　distribution　and　hydrophilicity.　Moreover,　filtration　tests　were　carried　out　to　explore　performance　and　mechanisms　of　fouling　control　by　the　enhanced　ferric　coagulation.　The　results　indicated　that　both　Fe(II)/permanganate　and　Fe　(II)/persulfate　could　improve　rejection　of　extracellular　organic　matter　by　20%-40%,　in　particularly　for　humiclike　acid　and　protein-like　substances.　Fe(II)/persulfate　outperformed　Fe(II)/permanganate　in　alleviating　the　flux　reduction　by　extracellular　organic　matter.　Simultaneous　oxidation　and　coagulation,　which　were　associated　with　in　situ　formed　sulfate　radicals　and　Fe(III),　respectively,　were　the　principal　mechanism　for　fouling　control.　The　enhanced　ferric　coagulation　only　slightly　improved　the　fouling　reversibility,　and　iron　and　manganese　oxides　deposited　in　the　external　cake　layer　rather　than　inside　the　membrane.　Fe(II)/permanganate　did　not　significantly　changes　pattern　of　fouling　development,　whereas　Fe(II)/persulfate　induced　a　shift　of　fouling　mechanisms　from　dual　pore　blocking　and　cake　filtration　to　single　intermediate　blocking.　Overall,　the　strong　oxidation　(Fe(II)/　persulfate)　was　more　beneficial　to　the　control　of　membrane　fouling　by　extracellular　organic　matter　than　the　moderate　oxidation　(Fe(II)/permanganate).