The removal of phenolic compounds from aqueous medium by rice husk-based active carbons (RHCs) was first demonstrated. Factors of influence on the RHCs adsorbability were examined in detail. Two series of RHCs were derived by KOH-activation and NaOH-activation at different temperatures for various time, respectively. The difference in the adsorption performance for phenolic compounds were compared and elucidated by their pore size distribution, surface functional groups and the electric capacity, the results showed that the adsorption mainly took place on the external surface and was controlled by chemisorption and increased with the total density of carboxylic and lactonic. (C) 2004 Published by Elsevier B.V.