Iron-manganese　composited　oxide　(FeMnO)　was　prepared　with　potassium　permanganate　and　ferrous　salt.　Interface　performance,　charge　property　and　structure　topography　of　the　FeMnO　were　investigated.　Coagulation　efficiency　and　pollution　removal　mechanism　of　the　FeMnO　were　approached.　Results　show　that　the　main　compositions　of　the　FeMnO　are　delta-manganese　dioxide　and　ferric　hydroxide.　The　specific　surface　area　is　about　146.22　m(2)/g.　The　FeMnO　contains　rich　hydroxyl　with　extremely　strong　adsorption　action　and　chemical　adsorption　activity.　The　zero　charge　point　of　the　oxide　in　pure　water　is　about　8.0　of　pH　value.　Under　neutral　pH　value　conditions,　the　FeMnO　particle　surface　carried　positive　charges.　The　FeMnO　particles　are　quasi-spherical　micro-particles　with　irregular　sizes　adjoined　each　other　to　form　net　construction.　Phosphorus　removal　efficiency　of　the　FeMnO　is　remarkable,　the　total　dissoluble　phosphorus　of　settled　water　can　be　reduced　below　detecting　level　(0.3　mu　g/L)　at　a　FeMnO　dosage　of　6　mg/L,　and　total　phosphorus　below　detecting　level　at　a　FeMnO　dosage　of　10　mg/L,　for　water　samples　containing　total　phosphorus　of　1281.70　mu　g/L　and　total　dissoluble　phosphorus　of　1187.91　mu　g/L.　The　mechanism　of　effective　coagulation　for　phosphorus　removal　is　combined　results　of　multiple　actions　of　adsorption,　charge　neutralization,　adsorption/bridging　and　so　on.