The　VFA　(Volatile　Fatty　Acid)　produced　during　the　digestion　of　surplus　sludge　can　be　used　as　an　additional　carbon　source　for　nitrogen　and　phosphorus　removal　in　waste　water　treatment　process.　In　order　to　evaluate　effects　of　surfactants　on　the　effective　carbon　source　in　the　Autothermal　Thermophilic　Micro-Aerobic　Digestion　system　(ATMAD)　and　promote　the　development　of　internal　carbon　sources　by　using　RL　(Rhamnolipid)　as　a　typical　biosurfactant.　The　results　show　that　the　amount　of　VFA　significantly　increased　with　an　appropriate　amount　of　RL,　and　the　main　indexes　such　as　SCOD,　VFA,　protein　and　polysaccharide　in　the　supernatant　were　highly　improved.　The　sludge　dissolution　effect　significantly　increased　with　an　addition　of　RL　by　0.02　~　0.07g/gTSS.　The　release　of　soluble　organic　matter　and　accumulation　of　VFA　in　the　reaction　system　increased　and　be　up　to　the　highest　and　fastest　when　the　RL　dosage　was　0.07g/g　TSS.　In　addition,　increasing　the　concentration　of　bacteria　related　to　acid　production　fermentation　(such　as　Bacteroides　and　Clostridium)　could　effectively　promote　the　accumulation　of　volatile　fatty　acids.　Evidently,　an　appropriate　dosage　of　rhamnolipid　can　lead　to　a　high　feasibility　and　practicability　for　developing　high-quality　external　carbon　sources　ATMAD　system.　©　2024　Chinese　Society　for　Environmental　Sciences.　All　rights　reserved.