In order to remove mercury ions, Hg(II)-ion-imprinted polymers (Hg-IIPs) with silica core were synthesized by radical polymerization using complexes of Hg(II) ions with 3-mercaptopropyltrimethoxysilane ligands as a template, vinyltrimethoxysilane as a monomer, and ethylene glycol dimethacrylate as a crosslinker, in the molar ratio 1: 6: 6. Silica, thiol, vinyl, carbonyl, and Hg(II) in the synthesis process were detected through FTIR, SEM-EDS, TGA, and BET analyses. Using Hg-IIPs as the sorbent, mercury ion removal was near optimal from a batch at pH 4 with an interaction time of 90 min, and gave 62.27 mg.g-1 adsorption capacity. The capture by Hg-IIPs of Hg(II) ions in the presence of Pb(II), Cd(II), and Cu(II) ions in quaternary solutions had the selectivity coefficients 46.92 for Hg/Cu, 16.82 for Hg/Cd, and 2.07 for Hg/Pb.