Abstract: The adsorption behavior of nano-Al2O3 towardst thallium (Tl) was investigated.The test included sorption thermodynamics,effect of pH on adsorption ratio,and adsorption capacity.Under the optimum conditions,Tl(Ⅲ) ions could be adsorbed and recovered quantitatively.The maximum adsorption capacity of thallium ions on nano-Al2O3 was 4.44,5.78 mg·g-1,and 6.28 mg·g-1 at 2,20 ℃ and 40 ℃,respectively.The Langmuir model could describe the adsorption of nano-Al2O3 to Tl(Ⅲ) ions successfully over the whole range of studied concentration.The value of standard enthalpy and standard entropy (Δ H0 ,Δ S0 >0) may be interpreted as the endothermic adsorption process.The negative value of Δ G0 showed the adsorptions of Tl(Ⅲ) by nano-Al2O3 were a spontaneous process.For the elution of Tl(Ⅲ),the desorption percentage reached to 98% by 1.00 mL of 0.25 mol·L-1 HCl.Detection limits (3 σ ) of 0.84 μg·L-1,relative standard deviation of 2.4% level were obtained.The method has been successfully applied for determination of trace elements thallium in some environmental samples and the certified reference material (GBW07296) with satisfactory results.