A new activated carbon was manufactured with sawdust from plantation grown tripoloid populus tomentosa by dipping in phosphoric acid and baking under high temperature.Moreover,the adsorption capability of the carbon was also tested.From the results,the proper conditions of making the activated carbon were ascertained as follows:H3PO4 concentration of 55%,ratio of solid to liquid was 1∶2,baking under 400 ℃ for 4 h,and sawdust diameter of 40,6,0 mu.The activated carbon exhibited the most efficient adsorption capacity for alkalinity fuchsine for 4 h at pH 7 and 30 ℃.The carbon could regenerate six times without degrading the adsorption capability.Its adsorption capability was comparable to the commercial activated carbons.