For　photocatalytic　reaction　arises　on　the　catalyst＇s　surface,　only　contaminants　contacted　with　catalyst　can　be　decomposed.　Photocatalytic　reaction　rate　is　higher　under　the　higher　initial　pollutant　concentration.　However,　the　concentration　of　indoor　pollutants　is　usually　very　low.　In　order　to　enhance　the　photocatalytic　reaction　rate　of　contaminants　in　indoor　pollutants　level,　this　paper　immobilized　the　TiO2　on　the　activated　carbon　(AC)　to　improve　the　local　concentration　of　contaminants　on　the　surface　of　photocatalyst　TiO2　by　the　absorption　of　AC.　So　the　indoor　contaminants　with　low　level　concentration　can　be　decomposed　to　the　range　of　indoor　air　quality　standards.