Cyanobacterial　blooms　generated　by　nutrient　addition　into　aquatic　systems　pose　serious　risks　to　ecosystems　and　human　health.　Though　there　are　established　chemical,　physical,　and　biological　means　of　eradication,　more　efficient　and　environmentally　friendly　measures　are　desired.　This　study　investigates　the　effect　of　potassium　ferrate(VI)　on　the　growth　and　intracellular　and　extracellular　organic　matter　accumulations　of　the　cyanobacterium　Microcystis　aeruginosa.　Cultures　were　inoculated　with　three　separate　concentrations　of　potassium　ferrate(VI)　(3,　15,　30　mg　L-1)　and　monitored　by　measuring　chlorophyll-a　(Chl-a)　and　intracellular/extracellular　dissolved　organic　carbon.　Results　show　that　ferrate(VI)　addition　effectively　removed　the　microalgae　from　the　medium,　as　indicated　by　the　reduction　of　Chl-a.　Organic　matter　accumulation　of　the　microalgae　was　also　affected　by　ferrate(VI)　treatment;　fluorescence　EEM　spectra　show　details　of　changing　intracellular　dissolved　organic　matter　(IDOM)　and　extracellular　dissolved　organic　matter　(EDOM).　A　new　peak　appeared　in　the　EDOM　indicating　altered　humic　and　proteinaceous　compounds.　This　study　demonstrates　that　ferrate(VI)　is　a　potential　treatment　for　the　water　contaminated　with　the　toxic　microalgae　M.　aeruginosa.