Activated carbon is of a porous type material. Adsorption of dyes of different types is dependent on the pore sizes of activated carbon. The relation between pore structure and properties of dyes is an important factor on the amount of the adsorbed dye. The comparison in terms of colour removal of textile wastewater is made among different dyes of activated carbon, structure of pores and the specific characteristics of pores. In this study, the optimum conditions of colour removal by different types of activated carbons were investigated. Adsorption characteristics between different dyes in wastewater and activated carbon types were also studied. The removal efficiency of activated carbon has been compared with other methods and optimal conditions of treatment system have been reinvestigated.