Volatile organic compoudns (VOCs) include more than 60% of total hazardous air pollutants that are emitted by most industrial field. Activated carbons play an important role in the purification of air and of water. Adsorption by an activated carbon has been recognized as one of the feasible regenerative control processes to separate and recover VOCs for reuse. Adsorption characteristics of VOCs by adsorbents (activated carbon) were investigated using a continuous generation system for VOCs. As samples of VOCs, toluene gas was adopted. In this study, Korean watermelon-seed was used to prepare activated carbon from roasting, carbonization and chemical activation, respectively. The adsorbate benzene gas was determined adsorption capacity using the adsorption apparatus with Cahn balance system.