By　taking　two　natural　clays　and　two　clay　minerals　of　calcium　bentonite　and　sodium　bentonite　as　the　source　of　soil,　the　diesel　oil　contaminated　soils　with　different　contents　of　diesel　oil　and　different　water　contents　were　prepared.　The　tests　for　the　water　contents　and　the　Atterberg　limits　of　the　diesel　oil　contaminated　soils　were　performed.　A　new　concept　was　proposed　for　describing　the　initially　volatile　contents　of　the　diesel　oil　contaminated　soils,　and　a　new　calculation　method　for　the　water　contents　of　the　diesel　oil　contaminated　soils　was　described　by　considering　both　the　volatility　of　diesel　oil　and　the　adsorption　of　diesel　oil　by　clay　particles.　The　results　that　show　the　liquid　limits　and　the　plastic　limits　of　the　diesel　oil　contaminated　soils　prepared　with　original　natural　clays　increase　firstly　and　then　decrease　with　the　increase　of　the　content　of　diesel　oil.　The　liquid　limits　of　the　diesel　oil　contaminated　soils　prepared　with　two　clay　minerals　of　calcium　bentonite　and　sodium　bentonite　decrease　monotonously　with　the　increase　of　the　content　of　diesel　oil,　but　contrary　trends　are　found　for　the　plastic　limits.　The　influence　of　diesel　oil　on　the　plastic　limits　is　obviously　greater　than　that　on　the　liquid　limits.　In　addition,　the　plasticity　indices　of　the　diesel　oil　contaminated　soils　prepared　with　two　clay　minerals　of　calcium　bentonite　and　sodium　bentonite　decrease　monotonously　with　the　increase　of　the　content　of　diesel　oil,　but　contrary　changing　laws　are　found　for　the　diesel　oil　contaminated　soils　prepared　with　natural　clays.　©　2016,　Editorial　Department　of　Journal　of　Southeast　University.　All　right　reserved.