Activated carbon was prepared from cotton woven waste with potassium hydroxide. X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental analyzer, FTIR spectroscopy and specific surface area and pore size analyzer were employed to characterize the activated carbon. Firstly, carbonized the cotton woven waste. Then prepared activated carbon at the optimum conditions of the carbon to activated agent ratio of 1:1, immersion time of 16 h, temperature of 850 ℃ and holding time of 50min.The results show that under the optimum conditions, activated carbon has a sophisticated pore structure with specific surface area of 1368.67 m2/g and a total volume of 0.6208 cm3/g. The micropore specific surface area and pore volume account for 75% and 71.63%, respectively. The micropores size were between 0.84~1.3 nm. Activated carbon was hollow fiber with a 90.55% carbon content. The surface functional groups were mainly hydrophilic groups such as carboxyl, carbonyl, hydroxyl and so on. The study shows that the cotton woven waste can be used for the preparation of activated carbon.