The electrode properties of manganese dioxides prepared by the reduction with various reagents were examined. The particle size and morphology depended on reducing agents. Some samples obtained were aggregated round particles of submicron order and the others were fine needle-like shape of a few nanometers in width and several tens of nanometers in length. The former showed around 200 mA h/g, while the later showed high capacity of 500 mA h/g in the open circuit voltage (OCV) measurements until 1 V (vs. Li). The cell assembled with Li anode showed a good cycle performance in the range of 3.9-2.0 V with a capacity of 150 mA h/g.