Two new crosslinked-crown ethers (CCTS-NACH-B-15-C-5 and CCTS-NACH-B-18-C-6) were synthesized by the reaction of crosslinked chitosan (CCTS-NH 2 ) with 4Ј-formyl benzo-15-crown-5 and 4Ј-formyl benzo-18-crown-6. Their structures were confirmed with elemental analysis, infrared spectra analysis, solid-state 13 C NMR analysis, X-ray diffraction analysis, and differential scanning calorimetry thermogram analysis. In the infrared spectra of CCTS-NACH-B-15-C-5 and CCTS-NACH-B-18-C-6, the characteristic peak of CAN stretch vibration appeared at 1650 cm Ϫ1 . The X-ray diffraction analysis showed that the peak at 2 ϭ 20°decreased greatly in CCTS-NACH-B-15-C-5 and CCTS-NACH-B-18-C-6. In the 13 C NMR spectra of CCTS-NACH-B-15-C-5 and CCTS-NACH-B-18-C-6, the characteristic peak of aromatic carbon appeared at 128-ppm, the characteristic peak of carbon in the CAN group appeared at 151 ppm. The adsorption and selectivity properties of CCTS-NACH-B-15-C-5 and CCTS-NACH-B-18-C-6 for Ag ϩ , Pd 2ϩ , Pb 2ϩ , Cd 2ϩ , and Cr 3ϩ were studied. The experimental results showed that the two crosslinked chitosan-crown ethers have not only good adsorption capacities for Ag ϩ and Pd 2ϩ , but also high selectivity for the adsorption of Ag ϩ or Pd 2ϩ with the coexistence of Pb 2ϩ and Cr 3ϩ . The selectivity coefficients of CCTS-NACH-B-15-C-5 and CCTS-NACH-B-18-C-6 were K Pd 2ϩ /Pb 2ϩ ϭ 9.9, K Ag ϩ /Pb 2ϩ ϭ 9.8, K Pd 2ϩ /Cr 3ϩ ϭ ϱ, K Pd 2ϩ /Pb 2ϩ ϭ 11.5, K Ag ϩ /Pb 2ϩ ϭ 7.1, K Pd 2ϩ /Cr 3ϩ ϭ ϱ, respectively.