Abstract: Activated carbon was prepared from bamboo by mechanochemical process with phosphoric acid as activating agent. The effects of milling time on the adsorption property and porous structure of the obtained activated carbon were discussed. The results showed that phosphoric acid activation assisted by mechanochemical process can slightly improve the adsorption performance of the prepared activated carbon. The iodine, methylene blue adsorption value and the specific surface area of the prepared activated carbons increased from 840.16 mg/g, 168 mg/g and 1229.246 m2/g to 947.51 mg/g, 195 mg/g, and 1265.373 m2/g, respectively. Compared with conventional phosphoric acid activation, the activated carbon produced by mechanochemical process has greater adsorption capacity.