The　infiltration　effect　of　Cu2+　on　permeability　properties　of　soil　was　studied.　In　experiments,　artificial　used　CuCl2　solution　was　employed　as　penetrant.　A　triple　type　flexible-wall　permeameter　was　used　to　study　the　permeability　properties　of　contaminated　soil　under　two　different　conditions,　by　which　the　influence　of　confining　pressure　and　the　penetrant　on　concentration　the　permeability　properties　of　soil　were　evaluated.　Results　show　that　when　the　concentration　of　CuCl2　solution　was　kept　constant,　regardless　of　penetrant　as　pure　water　or　CuCl2　solution,　the　permeability　coefficient　of　clay　decreased　with　the　increase　of　confining　pressure.　While　under　the　same　confining　pressure,　the　permeability　coefficient　of　clay　with　the　CuCl2　solution　as　the　penetrant　was　less　than　that　with　the　pure　water　as　the　penetrant.　In　addition,　while　confining　pressure　increased,　the　permeability　coefficient　gradually　decreased　until　the　confining　pressure　was　more　than　500　kPa　and　the　impact　of　penetrant　on　the　permeability　of　soil　was　small.　When　the　confining　pressure　was　kept　constant,　while　the　concentration　of　penetrant　varies,　the　permeability　coefficient　of　clay　decreased　rapidly　at　first　and　then　gradually　increased　with　the　concentration　of　CuCl2　solution.　The　results　on　micro-structure　analyzing　show　that　the　permeability　coefficient　of　clay　with　CuCl2　solution　as　the　penetrant　was　different　from　that　of　pure　water,　as　the　penetrant,　which　may　be　attributed　to　the　fact　that　Cu2+　erosion　could　change　the　internal　structure　of　clay　and　as　a　result　lead　to　the　differences　in　the　macroscopic　permeability.