Abstract: Hydrated manganese oxide (MnO) is prepared with potassium permanganate and sodium subsulfite. Interface performance, charge property and structure topography of MnO are investigated. Turbidity and organic matters removal efficiency by coagulation, and coagulation mechanism of MnO are approached. Results show that the zero charge point of the MnO particles is about 1.8 of pH value (pH<sub<PZC</sub<) in pure water. MnO contains with rich hydroxyl with specific surface area of 131.59m<sup<2</sup<·g<sup<-1</sup<. MnO shows extremely strong adsorption action and chemical adsorption activity, and structure topography for easy adsorption bridging action. MnO is provided with better turbidity and organic matters removal efficiency by coagulation. Turbidity and TOC removal rate of the settled water are 77.94% and 49.15% respectively. MnO is provided with remarkable filtration aid action. The filtered water turbidity can be decreased below 0.01NTU under lower MnO dosage of 4mg·L<sup<-1</sup<. The main mechanism of coagulation for turbidity and organic matters removal is the actions of adsorption bridging and enmeshment rolling sweeping.