Short fibrous hollow activated carbons with a high aspect ratio were prepared by carbonization and carbon dioxide activation of softwood and hardwood fibers. The softwood activated carbon consisted mostly of micropores even though the degree of burn-off during the activation became higher. In the case of the hardwood fiber, on the other hand, meso- and macropores as well as micropores were formed and the ratio of these large pores increased with an increasing degree of burn-off. The adsorbed amount of water and toluene vapor on these fibrous activated carbons was compared with that of the commercial activated carbon fibers (ACFs). These fibrous activated carbons showed a high adsorption capacity comparable to that of the ACFs. (C) 2004 Kluwer Academic Publishers.