External　organic　sources　could　make　up　for　the　lack　of　carbon　in　the　treatment　of　chlorophenol;　but　the　impact　on　external　carbon　concentration　on　the　degradation　of　2,4,6-trichlorophenol　(2,4,6-TCP)　has　rarely　been　studied.　In　this　study,　the　effect　of　carbon　addition　on　the　degradation　of　2,4,6-TCP　was　investigated　using　the　labscale　sequencing　batch　reactor　(SBR).　The　results　indicated　that　excessive　carbon　amounts　inhibited　2,4,6-TCP　degradation　in　the　long-term　operation　and　a　typical　cycle,　while　a　suitable　dosage　could　increase　the　removal　of　2,4,6-TCP.　The　application　of　external　carbon　rapidly　decreased　the　dissolved　oxygen　level　of　the　system,　resulting　in　inhibited　chlorophenol　removal.　The　concentration　of　removed　2,4,6-TCP　could　be　increased　from　35.49-152.89　mg　L-1　by　adjusting　the　carbon　dosage.　At　the　phylum　level,　Proteobacteria　and　Acidobacteria　phylum　bacteria,　related　to　2,4,6-TCP　removal,　were　dominant　when　no　carbon　source　was　added,　while　excessive　carbon　levels　resulted　in　the　overgrowth　of　Saccharibacteria　(50.19　%),　responsible　for　carbon　metabolism.　In　co-metabolism　systems,　chlorophenol-contaminated　wastewater　can　effectively　be　treated　by　adjusting　the　external　carbon　source.