The　adsorption　efficiency,　isothermal　adsorption　and　kinetics　of　durian　shell　modified　by　citric　acid　for　Pb(II)　and　Cr(III)　from　aqueous　solution　was　investigated.　Both　modified　and　unmodified　adsorbents　were　characterized　by　FT-IR,　SEM　and　XPS,　and　modification　and　adsorption　mechanism　of　durian　shell　was　discussed.　The　results　of　FT-IR　and　XPS　demonstrated　that　after　modified　by　citric　acid　via　N,　N＇-carbonyldiimidazole　as　a　activator,　the　new　peaks　at　1730　and　1640　cm-1were　assigned　to　ester　carbonyl　groups　and　carboxylate　stretching　band　on　durian　shell　and　the　m(O)/m(C)　atom　mass　ratio　increased,　which　indicated　the　presence　of　citric　acid　grafted　onto　durian　shell.　Adsorption　results　showed　that,　the　adsorption　capacity　of　durian　shell　modified　by　citric　acid　for　Pb(II)　and　Cr(III)　were　3.15　and　2.42　times　as　those　of　the　natural　durian　shell,　respectively.　The　adsorption　of　Pb(II)　on　durian　shell　modified　by　citric　acid　exhibited　a　stronger　competitive　effect　than　Cr(III)　in　the　aqueous　solution　with　two　coexisting　anions.　The　adsorption　kinetics　data　showed　that　the　adsorption　equibrium　was　reached　in　120　min　for　Pb(II)　and　Cr(III)　and　the　data　of　adsorption　rate　could　be　described　by　pseudo-second-order　rate　model　(R2＞0.9975).　At　25　degrees　celsius,　the　isothermal　adsorption　of　Pb(II)　and　Cr(III)　on　durian　shell　modified　by　citric　acid　tended　to　be　fitted　well　by　the　Freundlich　model　(R2＞0.9902).　Adsorption-desorption　results　showed　that　the　CM-CDI-DRS　remained　high　biosorption　ability　for　Pb(II)　after　four-time　usage.　©　2015,　Chongqing　Functional　Materials　Periodical　Press　Co.　Ltd.　All　right　reserved.