Abstract: The adsorption of two kinds of chromium compounds (Cr(Ⅲ) and Cr(Ⅵ)) on bentonites was examined. Freundlich and Langmuir isotherm was suggested as the most appropriate type for the two compounds by comparing three different equations. The maximum adsorbance of trivalent is 0.47 mg/g. The influence of some factors such as pH value on the adsorption was investigated, and that of lime and two kind of surfactants (SN-1 and ABSN) on the adsorption was also discussed.