Effects of organic acids (acetic acid,tartaric acid and citric acid) on Cd²⁺ and Pb²⁺ adsorption on goethite and bentonite were studied with the batch method.Results show that pH decreased with the increase in concentration of Cd²⁺ and Pb²⁺ in the goethite and bentonite isothermal systems when the concentration of Cd²⁺ and Pb²⁺ was lower than 0.2 mmol L^-1 and 4.0 mmol L^-1,respectively.The decrease of pH in bentonite system was more obvious than in goethite system.The effect of pH on Cdand Pbadsorption of goethite and bentonite varied sharply with organic acids added.Cd²⁺ sorption rate was small with goethite when pH was in the range from 3 to 4.5,but it went upward sharply when pH was higher (4152+ sorption rate began to increase when pH was 3 with goethite,and it leveled off to 95% at pH 5.5.Affected by three organic acids,Cd²⁺ sorption rate increased slowly from 40% at pH 3 with bentonite,and approached close to 90% at pH 8.Pb²⁺ sorption rates were around 60% in bentonite systems added with different organic acid.They increased to 80% when citric acid was added and 95% when other organic acid added.Cd²⁺ and Pb²⁺ sorption rates varied from 40% to 90% with bentonite at different pH,but from 3% to 90% with goethite.In terms of effect of organic acids on Cd²⁺ and Pb²⁺ adsorption of goethite,the three acids were in the order of citric acid > tartaric acid > acetic acid,but the effect was not clear with bentonite.