The adsorption characteristics of amatanth by granular activated carbon were experimently investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for amaranth were largely improved by pH control, and 94 percent of initial concentration(100mg/L) could be removed at pH 9. It was estabilished that the adsorption equilibrium of amaranth on granular activated carbon was sucessfully fitted by Freundlich isotherm equation in the concentration range from 1mg/L to 100mg/L. The characteristics of breakthrough curve of activated carbon packed column, which depend on the design variables such as initial concentration, bed height, and flow rate, were studied.