Adsorption characteristics of chloroform and bromoform onto activated carbon fibers (ACFs) for the safety drinking water were investigated. The amounts of chloroform and bromoform adsorbed onto ACFs decreased with their grade number that is the surface area and pore volume. Bromoform was more easily adsorbed onto ACFs than chloroform due to the difference in water solubility. The dominant factor of chloroform and bromoform adsorption onto ACFs may be the surface hydrophobicity of adsorbent rather than the surface area or pore volume.