Photocatalysis　is　an　emerging　and　promising　technology　for　indoor　air　purification.　This　photocatalytic　oxidation　(PCO)　method　is　effective　in　the　case　of　a　higher　pollutant　concentration,　but　its　wide　application　in　indoor　air　purification　is　limited　due　to　the　low　level　of　indoor　air　contaminants.　In　order　to　improve　the　removal　of　pollutants　in　indoor　air,　we　have　evaluated　the　photocatalytic　performance　over　the　nanosized　TiO2　particles　immobilized　on　the　surface　of　an　activated　carbon　(AC)　filter　for　the　removal　of　formaldehyde　(HCHO).　However　the　pollutant　removal　capacity　is　low　at　the　low　level　of　indoor　HCHO　over　the　TiO2/AC　film　because　the　predominant　influence　of　residence　time　during　this　reaction.　In　order　to　improve　the　photocatalytic　removal　amount　of　formaldehyde　(HCHO)　in　indoor　air,　we　studied　the　combining　effect　of　photocatalysis　technology　with　a　non-thermal　plasma　(NTP)　technology　on　the　removal　of　in　door　HCHO.　Two　different　plasma　electrode　configurations,　that　is　wire-to-plate　and　needle-to-plate　electrode　configuration,　were　built　and　the　removal　of　HCHO　was　studied　by　experiment.　The　experimental　results　showed　that　the　wire-to-plate　electrode　configuration　is　more　effective　for　the　HCHO　removal　than　the　needle-to-plate　electrode　configurations.　The　experimental　results　using　wire-to-plate　electrode　configuration　showed　that　the　removal　of　HCHO　can　be　enhanced　and　the　removal　amount　of　indoor　HCHO　can　be　improved　by　the　combination　of　PCO　and　NTP　and　the　combination　of　PCO　and　NTP　showed　the　synergetic　effect　for　the　indoor　HCHO　removal.　So　the　combination　of　PCO　and　NTP　might　be　a　good　route　for　the　practical　application　of　photocatalytic　technology　in　indoor　air　purification.　Copyright　©　2009　by　ASME.