The　chemical　characteristics　of　trapped　liquid　and　the　corrosion　features　of　X70　pipeline　steel　under　a　disbonded　coating　in　a　simulated　solution　of　Kuerle　soil　were　studied　by　using　the　rectangular　stripping　gap　model.　With　the　increasing　of　test　time,　the　pH　value　of　trapped　solution　gradually　declines　and　finally　reaches　a　stable　level.　Cl-　has　different　degrees　of　gathering　and　its　highest　concentration　occurs　in　the　end　of　the　gap.　The　concentration　of　SO42-　decreases　at　the　initial　stage　but　increases　at　the　late　stage,　the　concentrations　of　HCO3-　and　NO3-　decrease　slightly　from　the　holiday　to　the　end,　and　the　concentration　change　of　cations　is　not　obvious　or　only　a　minor　reduction.　The　corrosion　morphology　of　X70　steel　under　the　disbonded　coating　performs　obvious　pitting　corrosion,　which　is　much　more　serious　with　the　increasing　of　distance　from　the　holiday.　©,　2014,　University　of　Science　and　Technology　Beijing.　All　right　reserved.