The adsorption capability of nano-barium-strontium titanate coated by dithizone(BST- dithizone) for mercury in environmental water samples was studied. The optimum experimental parameters for the adsorption and desorption of the mercury, such as pH values, contact time and eluent, have been investigated. The results showed that the mercury ion in water could be adsorbed on the BST- dithizone. The adsorption capability was affected by the pH value of medium and contact time. In the medium of pH 3-8, the adsorption time was more than 15 min, and capacity of adsorption was 15.3 mg·g-1. The used adsorbent could be completely regenerated using 2 mol·L-1 HNO3. A new method for the removal of mercury in water samples was proposed. The method has been applied to the removal of mercury in waste water samples with satisfied results.