Composite electrodes for redox supercapacitor were prepared potentiodynamically by the deposition of RuO2 and the co-deposition of Ru-Co mixed oxide on the surface of single-walled carbon nanotube. Electrode of Ru-Co mixed oxide, in which Ru(13.13 wt%) and Co(2.89 wt%) were deposited on the carbon nanotube, exhibited a similar specific capacitance(~620 F g-1) with RuO2 electrode at a low potential scan rate(10 mV s-1), but showed a superior one (570 F g-1) at a high scan rate(500 mV s-1) than that of RuO2(475 F g-1). Such increase in the specific capacitance at high scan rate by the co-deposition of Ru and Co species was due to the structural support of Co species to provide the electronic conduction through Ru species.