We report the fabrication of uniform large-area manganese oxide (MnO2) nanosheets on carbon fabric which oxidized using O2plasma treatment (MnO2/O2-carbon fabric) via electrodeposition process and their implementation as supercapacitor electrodes. Electrochemical measurements demonstrated that MnO2/O2-carbon fabric exhibited capacitance as high as 275 F/g at a scan rate of 5 mV/s; in addition, it showed an excellent cycling performance (less than 20% capacitance loss after 10,000 cycles). All the results suggest that MnO2/O2-carbon fabric is a promising electrode material which has great potential for application on flexible supercapacitors.