A novel type of hybrid membrane was fabricated by incorporating hydrophilic bacteria cellulose(BC)nano fibers into Nafion for the applicationin proton exchange membrane fuel cells.With the introduction of BC nano fiber network membranes,a large amount of hydroxyl groups in Nafion aggregated onto the interfaces between BC fibers and the ionomer matrix,forming continuous path ways for facile proton transport.The resultant hybrid membranes had higher protoncon ductivities than that of recast Nafion,and the conductivities were controlled by selectively adjusting the BC fiber content.Based on the results of this study,hybrid membranes fabricated by ionomers,such as Nafion,incorporated with hydrophilic BC nanofibers established a promising strategy for the rational design of high-performance proton exchange membranes.