Activated carbon was prepared from rice hull by chemical activation with KOH. The preparation process was carried out by roasting carbonization, chemical activation, washing, and drying. Carbonization process was carried out at 750 ℃, 1hr. Chemical activation process was carried out by using KOH as an activation agent at 800 ℃, 1hr N2-BET surface areas were measured as about 610~1342 m(2)/g with 100~300 wt% chemical ratio of KOH. Total pore volume and average pore radius were determined as about 0.34~1.12 cm(3)/g and 25-35Å, respectively.