The mechanical tests in compression of swollen carboxylic cation-exchange resins with different structure and composition have been done. Cation-exchange resins consist of methacrylic acid and cross-linking agent units or acrylic and methacrylic acids and cross-linking agent units. The response of cation-exchange resins to mechanical influence has been analyzed at compression 5, 10, and 25 MPa. The data obtained have been correlated with network structure which was displayed also in specific swelling values and sorption of Cu(II) ions on H+-form of cation-exchange resins.