The p-chlorophenol (4-cp) adsorption to biofilm components was investigated by the experiment. Biofilm components included modeling water particulate (kaolin) with biofilm coating, bacterial cell, exopolysaccharide, kaolin and kaolin with exopolysaccharide. The adsorption of 4-cp in these systems could be described by Langmuir and Freundlich isotherm equations except the system of kaolin with exopolysaccharide. Under the condition of 25 degrees C and pH of 6.1 in these reaction systems, bacterial cell and EPS adsorbed more 4-cp than kaolin. The biofilm coating of kaolin affected its adsorption to 4-cp. Kaolin with biofilm coating adsorbed more 4-cp than that without biofilm coating.