DOM　is　often　utilized　as　a　control　parameter　in　the　design　of　water　treatment　process　as　well　as　others　such　as　water　treatment　efficiency　and　formation　of　disinfection　byproducts　(DBPs),　of　which　removal　and　characterization　have　received　wide　attention.　Fluorescence　excitation-emission　matrix　spectroscopy　(EEMs)　for　DOM　characterization　in　flocculation　process　at　present　is　not　well　known.　It　is　for　this　reason　that　the　EEMs　in　this　study　was　employed　to　characterize　the　Missouri　River　DOM　removal　by　the　flocculation　process.　The　results　showed　that　four　underlying　components　extracted　from　the　EEMs　of　DOM　by　parallel　factor　(PARAFAC)　were　humic　acid-like　(A),　fulvic　acid-like　(B),　protein-like　(C)　and　unidentified　component　(D),　while　the　Missouri　River　DOM　was　dominated　by　A,　B　and　C.　Flocculation　was　effective　for　the　hydrophobic　organic　compound　A　followed　by　the　hydrophilic　organic　compounds　B　and　C,　whereas　the　smallest　molecular　size　compound　C　was　hard　to　treat.　Further　study　illustrated　that　for　flocculation　at　pH　7,　higher　DOC　and　THM　removal　efficiencies　were　obtained,　and　that　the　correlations　of　DOM　components　with　DOC　and　THM　removal　efficiencies　were　significant,　thus　indicating　that　the　EEMs-PARAFAC　offers　a　robust　analytical　method　for　assessing　DOM　removal　efficiency　in　the　flocculation　process.　©　2014　Elsevier　B.V.