Four　polyaniline-tea　saponin　(PTS)　nanocomposites　were　prepared　by　an　in-situ　polymerization　with　tea　saponin　(TS)　as　a　biosurfactant,　and　they　were　used　to　remove　organic　dyes　from　aqueous　solution.　The　PTS　nanocomposites　were　characterized　by　using　field　emission　scanning　electron　microscopy,　the　Fourier　transform　infrared　spectroscopy,　the　Ultraviolet-visible　spectroscopy,　and　the　thermogravimetric　analysis.　The　adsorption　performances　of　the　PTS　nanocomposites　for　organic　dyes　were　studied　by　a　static　adsorption　method.　The　experimental　results　reveal　that　adsorption　capacities　of　the　PTS　nanocomposites　are　higher　than　that　of　pure　polyaniline.　Especially,　the　PTS　nanocomposites　exhibit　excellent　adsorption　performances　for　anionic　dyes　because　of　the　electrostatic　interaction　between　the　positively　charged　nitrogen　atoms　on　the　PTS　chains　and　the　negatively　charged　sulfonate　ions　in　the　anionic　dyes.　According　to　the　adsorption　kinetics　and　thermodynamics　results,　the　adsorption　processes　of　PTS20　for　CR　and　AB74　follow　well　with　the　pseudo　second-order　and　Langmuir　isotherm　models.　It　is　indicated　that　TS　should　be　very　useful　in　the　preparation　of　PTS　nanocomposite　and　in　removal　of　toxic　dyes　from　waste　water.　©　2021,　Wuhan　University　of　Technology　and　Springer-Verlag　GmbH　Germany,　Part　of　Springer　Nature.