Biological　control　of　odor　gases　has　gained　more　attention　in　recent　years.　In　this　study,　removal　performance　of　a　vertical　bio-trickling　filter　inoculated　with　bacteria　and　fungi　was　studied.　Bacteria　and　fungi　were　isolated　from　activated　sludge　in　a　sewage　treatment　plant.　By　adopting　＂three　step　immobilization　method＂,　the　bio-trickling　filter　could　degrade　pollutant　immediately　once　hydrogen　sulfide　(H2S)　passed.　The　optimal　empty　bed　resident　time　was　20　s.　The　optimal　elimination　capacity　was　about　60　g　H2S　m(-3)　h(-1)　with　removal　efficiency　of　95%.　And　the　maximum　elimination　capacity　was　170　g　H2S　m(-3)　h(-1).　Pressure　drop　was　ranged　between　5　and　15　mm　H2O　per　bed　over　the　whole　operation.　Removal　efficiency　was　not　affected　obviously　after　terminating　nutrient　supply.　The　bio-trickling　filter　could　recover　back　after　shut　down　H2S　gaseous　and　liquid　supplies　simultaneously.　Microbial　community　structure　in　the　bio-trickling　filter　was　not　changed　significantly.　Combining　bacteria　and　fungi　would　be　a　better　choice　for　inoculation　into　a　bio-trickling　filter　because　of　the　quickly　degradation　of　H2S　and　rapid　recovery　under　shut-down　experiment.　This　is　the　first　study　attempting　to　combine　bacteria　and　fungi　for　removal　of　H2S　in　a　bio-trickling　filter.　(c)　2012　The　Institution　of　Chemical　Engineers.　Published　by　Elsevier　B.V.　All　rights　reserved.