The hydrogen storage capacity of transition metal Ti atoms decorated porous fullerene C24B24 is investigated by the pseudopotential density functional method. The C24B24 cage contains six B4 rings with the average diameter of 3.88 Å. The Ti atoms are strongly bound to six B4 rings. Each Ti atom can adsorb up to six H2 molecules. The calculated average adsorption energies per H2 for (Ti-nH2)6C24B24(n = 1–6) are in the energy range from 0.24 to 0.55 eV, which is suitable for hydrogen storage at near-ambient conditions. The Dewar–Kubas interaction dominates the adsorption of H2 on the outer surface of Ti6C24B24. The largest hydrogen gravimetric density of (Ti–6H2)6C24B24 is 8.1 wt%, exceeding the 5.5 wt% by the year 2017 specified by the US department of energy (DOE). Therefore, the stable Ti6C24B24 can be applied as one candidate for hydrogen storage materials at near-ambient conditions.