Cation exchange capacity of clay, white clay and zeolite was estimated by performing the powder adsorption test for 6 different heavy metal (Cd, Cr, Cu, Fe, Pb and Zn) standard solutions whose concentrations were varied by 5,10,15 and 20 ppm. The adsorption rate of heavy metals decreased with increasing the concentration of standard heavy metal solutions. The adsorption rate of the clay and the white clay showed more than 80% for the all tested heavy metals except Cr and especially above 99% for the Fe and the Pb. The Cr adsorption rate of the mixture of the clay and the white clay increased, however, that of Zn decreased. The adsorption rate of Cr and Zn showed relatively lower values as compared with those of the other heavy metals because the cation exchange H$^$+/ ions and heavy metal ions of the clay or the white clay were in competition at low pH region.