Chestnut　shell,　an　agricultural　residue,　was　used　as　a　low-cost　adsorbent　to　remove　Reactive　Brilliant　Red　K-2G　(RBR)　from　aqueous　solution.　Batch　adsorption　experiments　were　conducted　to　study　the　effects　of　initial　solution　pH　value,　adsorbent　dosage,　initial　dye　concentration　and　temperature　on　the　adsorption.　It　was　proved　that　strong　acidic　condition　was　favorable　for　the　adsorption　process　and　the　optimal　pH　value　was　1.0.　Freundlich　isotherm　was　appropriate　for　describing　the　experimental　data.　The　kinetics　study　revealed　that　the　adsorption　of　RBR　onto　chestnut　shell　followed　the　pseudo-second　order　model　well.　The　external　mass　transfer　mainly　governed　the　adsorption　rate.　Thermodynamic　studies　demonstrated　the　spontaneous　and　exothermic　natures　of　the　adsorption　process.　The　FTIR　analysis　indicated　that　functional　groups　such　as　amine,　hydroxyl　and　phenolic　compounds　on　the　chestnut　shell　may　be　the　active　binding　sites　for　the　adsorption　of　RBR.