Abstract: A study on infiltration,transportation and transformation of hazardous and toxic heavy metal ions in compacted clayliner has been carried out.Indoor simulation experiments show that Pb and Cd (Ⅱ) ions,while transportation through the compacted clayliner,may produce indissoluble materials which prevent liquid from infiltrate into the compacted clayliner.Therefore,the permeability coefficients of Pband Cd (Ⅱ) inos would be smaller than that of pure water.In addition,experiments have been further made to study the effects of concentration and ion radius on permeability coefficient and transportation rate.