Two new crosslinked-crown ethers (CCTS-N=CH-B-15-C-5 and CCTS-N=CH-B-18-C-6) were synthesized by the reaction of crosslinked chitosan (CCTS-NH2) with 4＇-formyl benzo-15-crown-5 and 4＇-formyl benzo-18-crown-6. Their structures were confirmed with elemental analysis, infrared spectra analysis, solid-state C-13 NMR analysis, X-ray diffraction analysis, and differential scanning calorimetry thermogram analysis. In the infrared spectra of CCTS-N=CH-B-15-C-5 and CCTS-N=CH-B-18-C-6, the characteristic peak of C=N stretch vibration appeared at 1650 cm-l. The X-ray diffraction analysis showed that the peak at 2 theta = 20 degrees decreased greatly in CCTS-N=CH-B-15-C-5 and CCTS-N=CH-B-18-C-6. In the C-13 NMR spectra of CCTS-N=CH-B-15-C-5 and CCTS-N=CH-B-18-C-6, the characteristic peak of aromatic carbon appeared at 128-ppm, the characteristic peak of carbon in the C=N group appeared at 151 ppm. The adsorption and selectivity properties of CCTS-N=CH-B-15-C-5 and CCTS-N=CH-B-18-C-6 for Ag+, Pd2+, Pb2+, Cd2+, and Cr3+ were studied. The experimental results showed that the two crosslinked chitosan-crown ethers have not only good adsorption capacities for Ag+ and Pd2+, but also high selectivity for the adsorption of Ag+ or Pd2+ with the coexistence of Pb2+ and Cr3+. The selectivity coefficients of CCTS-N=CH-B-15-C-5 and CCTS-N=CH-B-18-C-6 were KPd2+/(Pb2+) = 9.9, KAg+/Pb2+ = 9.8, KPd2+/(Cr3+) = infinity KPd2+/(Pb2+) = 11.5, KAg-/Pb2+ = 7.1, KPd2+/Cr3+ = infinity respectively.