The developments of flexible supercapacitors are of great importance to the growing demand of portable electronic products. In the present work, we have successfully prepared bacterial cellulose (BC) membranes coated by polypyrrole (PPy) and copper oxide (CuO) as flexible composite electrodes for supercapacitor applications. The highest electrical conductivity value of 7.4 S cm(-1) was achieved using copper acetate aqueous solution with concentration of 1 wt%. Electrochemical measurements proved that the supercapacitors using the PPy/CuO/BC electrodes had a specific capacitance of 601 F g(-1) with an energy density of 48.2 Wh kg(-1) and a power density of 85.8 W kg(-1) at a current density of 0.8 mA cm(-2). The specific capacitance was kept at 385 F g(-1) after 300 cycles. The introduction of the CuO nanoparticles gave rise to the improved capacitance.