Swage　sludge　was　pretreated　by　using　thermal　hydrolysis　process　before　anaerobic　digestion.　The　digested　sludge　(dry-solids　of　12%)　was　thermally　pretreated　at　121°C　with　a　holding　time　of　30min.　The　results　showed　that　both　the　anaerobic　digestion　performance　of　thermally　hydrolyzed　sludge　and　treatment　efficiency　of　the　system　are　improved.　COD　and　VS　removal　rates　increased　from　37.6%　and　28.6%　to　48.2%　and　42.3%,　respectively.　The　biogas　per　gram　of　COD　added　were　increased　from　273.8mL/gTCOD　to　358.3mL/gTCOD,　and　the　yield　from　the　system　during　10　days　increased　by　83.9%　over　the　control.　Biogas　cumulative　volumes　and　rates　in　the　process　of　digestion　could　fit　well　with　specific　fountions,　respectively.　The　light　density　of　supernatant　fluid　from　anaerobic　digestor　indicated　the　value　of　E2　and　SUVA254　from　the　pretreated　sludge　one　was　appropriately　higher　than　the　control　one.　The　E4/E6　values　showed　humic　acid　generated　from　anaerobic　digested　sludge　was　similar　to　one　from　refuse　composting,　however,　had　a　lower　degree　of　molecular　weight　compared　to　one　from　soil.　It　concluded　that　the　content　of　humic　acid　produced　from　the　pretreated　sludge　was　more　than　the　control.　©　2011　IEEE.