Hydrogen storage in alkali metal-graphite intercalation compounds (AGICs) prepared from cup-stacked carbon nanofibers (A-CNFs, A = K, Rb and Cs) was studied by means of thermal desorption of hydrogen. The hydrogen sorbed to stage-1 K-CNFs amounts to 0.067 dm(3) (STP) per gram of carbon, most of which is fixed to KGIC as a chemical component.