Activated　carbon　was　prepared　from　coconut　shell　by　a　chemical　activation　method　with　potassium　hydroxide　at　different　temperatures　and　characterized　for　pore　structure.　The　adsorption　of　lysine　from　aqueous　solution　by　the　prepared　coconut　shell　activated　carbon　was　carried　out　using　batch　adsorption　experiments.　The　effect　of　shaking　speed,　adsorbent　dosage,　pH,　initial　lysine　concentration　and　temperature　were　investigated.　The　results　indicate　that　coconut　shell　activated　carbon　is　an　effective　adsorbent　which　has　a　high　surface　area　(1118.2　m(2)/g)　and　pore　volume　(0.4992　cm(3)/g).　The　effect　of　external　diffusion　is　negligible　at　170　rpm,　the　percent　removal　of　lysine　increases　with　the　increment　of　the　adsorbent　dosage,　the　optimum　pH　is　6.　The　adsorption　equilibrium　data　obtained　at　20,　30　and　40　degrees　C　agree　better　with　the　Langmuir　model　than　with　Freundlich　model,　and　the　thermodynamics　parameters,　Delta　H　=　2.71　kJ/mol,　Delta　S　=　107.2　J/mol.K　and　Delta　G　＜　0,　display　that　the　adsorption　process　is　spontaneous　and　endothermic.　The　adsorption　kinetics　is　well　described　by　the　pseudo　second-order　equation.　The　activated　carbon　was　successfully　regenerated　by　using　ammonia　as　eluent.　The　results　exhibit　that　coconut　shell　activated　carbon　is　an　efficient　and　low-cost　adsorbent　for　the　removal　of　lysine　from　aqueous　solutions.