In the determination of adsorbable organic halogen AOX, organic chlorine, organic fluorine and organic bromide in water and sewage, acticarbon is used to adsorb organic halogen compounds in water. Then the activated carbon is put into the high temperature furnace to burn, decompose and converted into hydrogen halide (hydrogen of fluorine, chlorine and bromine) . It is absorbed by alkaline aqueous solution and determined by ion chromatography.