A flexible electrode of NH4CoPO4 center dot H2O composite bacterial cellulose (Co-BC) has been successfully prepared via a hydrothermal method. A bacterial cellulose (BC) membrane was used as a host matrix for nanocrystalline (NC) NH4CoPO4 center dot H2O. The preparation process included anchoring nanocrystalline NH4CoPO4 center dot H2O on BC nanofibers with an intrinsic 3D network structure. X-ray diffraction (XRD) results indicated the orthorhombic structure of the NH4CoPO4 center dot H2O NC within the Pmn2(1) space group and BC of a Type-I structure. FE-SEM images revealed microplate-like NH4CoPO4 center dot H2O structures on BC nanofibers. The a three-electrode system of all samples were studied for their electrochemical properties by CV, charge/discharge and EIS estimations in a 3 M KOH electrolyte. A maximal specific area capacitance of 158.5 mF cm(-2)(43.3 F g(-1)) was obtained at a current density of 0.25 mA cm(-2)using a Co-BC90 electrode. Moreover, this sample show an excellent capacitance retention of 99% after a 3000 cycle at 1 mA cm(-2) current density.