Abstract: With the process of accelerative industrialization in China,the polluted foundation soil by industrial organizations had become serious environmental geotechnical problems.The properties of foundation soil have been changed by acid and alkali pollution.Soil specimens polluted by acid and alkali of 4 different concentration were artificially prepared.The compressible and deformable properties of polluted soil were studied.It was concluded that the rebound index,coefficient of compressibility and pre-consolidation pressure of polluted soil increased with the increase of the concentration,and the variation of the compression coefficient of soil polluted by acid was greater than that by alkali.All kinds of factors influencing the compressibility of polluted soil were analyzed,including grain-size distribution,plasticity index,moisture content and void ratio.The influence of variation of the compressibility of soil before and after pollution on the evaluation of the polluted foundation soil was studied.