Flower-like manganese wad(MW) with high activity was synthesized via ultrasonic-assisted redox reaction of sole manganese salt MnO4-.MW was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS).The experimental results indicate that the maximum decolorization rate of Congo red(CR) reached above 95% within 15 min in a wide pH range from 2.0 to 6.0.Results also show that MW has excellent decolorization performance for azo dye CR which implies potential application for removing dye pollutants from industrial effluents.