In this study, the capacity of hydrogen storage was evaluated by using electrospun activated carbon fibers prepared by electrospinning and chemical activation based on the comparison with other carbon materials such as active carbon, single walled carbon nanotube, and graphite. For an improved hydrogen storage system, the optimized conditions of carbon materials were investigated with studying their specific surface area, pore volume, size, and shape. The hydrogen adsorption capacity of chemically activated electrospun carbon fiber itself is better than that of other porous carbon materials. This is attributed to the optimized pore structure of electrospun activated carbon fibers that might provide better sites for hydrogen adsorption than other carbon materials. (C) 2009 Elsevier Ltd. All rights reserved.