Abstract: A modified bentonite was prepared,after the natural bentonite had been treated by heating,acidizing and ion exchange.Under the condition of static state,the adsorbing effects of modified bentonite compared with natural bentonite against heavy metal ions as Pb²⁺,Cr³⁺ and Ni²⁺ were studied.The adsorbing conditions and mechanism of modified bentonite against Pb²⁺,Cr³⁺ and Ni²⁺ was discussed at the same time.After the electroplating waste water which containing Pb²⁺,Cr³⁺ and Ni²⁺ was adsorbed by modified bentonite,the contents of Pb²⁺,Cr³⁺ and Ni²⁺ in waste water are prominently lower than discharge standard of China.