The　HLLS　(high　liquid　limit　soil)　has　the　characteristics　of　high　moisture　content,　low　bearing　capacity　and　poor　water　stability.　Most　of　the　existing　treatment　methods　focus　on　the　improvement　with　a　single　curing　agent,　and　the　research　on　the　improvement　of　HLLS　with　various　curing　agents　is　still　insufficient.　This　paper　presents　the　characteristics　of　two　kinds　of　compound　improved　HLLS　based　on　unconfined　compressive　strength　test.　The　results　show　that　the　unconfined　compressive　strength　of　CSIS　(Cement/SAP　Improved　Soil)　and　CLIS　(Cement/Renolith　Improved　Soil)　are　greatly　improved　than　those　of　CIS　(Cement　Improved　Soil)　when　the　curing　age　is　28d,　respectively.　The　maximum　increments　of　unconfined　compressive　strength　are　0.31MPa　and　0.22MPa,　respectively.　When　the　cement　content　is　less　(more)　than　3%,　the　unconfined　compressive　strength　of　CSIS　decreases　(increases)　with　the　increase　of　SAP　content.　When　the　cement　content　is　constant,　the　unconfined　compressive　strength　of　CLIS　increases　first　and　then　decreases　with　the　increase　of　the　Renolith　content.　The　optimum　mix　amount　of　SAP　(Renolith)　and　cement　in　CSIS　(CLIS)　are　0.06%　(0.2%)　and　5%　(3%),　respectively.　The　strength　and　crack　resistance　of　the　two　kinds　of　compound　improved　soil　are　better　than　the　one　with　single　curing　agent.　SAP　and　Renolith　exert　the　properties　of　self-curing　after　water　absorption　and　hydrophobicity,　respectively.　©　2017　Trans　Tech　Publications,　Switzerland.