An　activated　carbon　derived　from　sewage　sludge　was　prepared　by　orthogonal　test,　and　it　had　a　BET　surface　area　of　300.90　m(2)/g.　A　new　dechlorinating　agent　using　the　activated　carbon　as　the　main　active　component　was　studied.　The　agent　had　a　breakthrough　chlorine　content　of　19.38%　and　a　saturated　chlorine　content　of　37.32%　(under　conditions　of　200　square,　3000　h(-1)　space　velocity,　0.45　similar　to　0.90　mm　particle　size　and　5120　similar　to　5423　mg/m(3)　input　concentration).　The　effects　of　space　velocity,　temperature　and　particle　size　on　the　HCl-removal　behavior　of　the　sorbent　and　the　saturation　curve　ware　also　studied　in　this　paper.