Gel adsorbent produced through the copolymerization reaction between the N-isopropylacrylamide (NIPAM), and N,N-dimethyl(acrylamidopropyl)ammonium propane sulfonate (DMAAPS) has the capability to absorb and desorb ion simultaneously by temperature swing. In this study, NIPAM was used as thermosensitive agent and DMAAPS was used as adesorption agent. The effects of monomer concentration on the swelling, adsorption, and desorption properties of ions of thermosensitive NIPAM-co-DMAAPS gel were investigated at various temperatures and solution concentrations. NaNO3 solution was selected as the target solution and used in swelling, adsorption, and desorption test. The results showed that the swelling degree of the copolymer gel increase as temperature, solution, and NIPAM concentrations increase. The amount of ions adsorbed onto the copolymer gel increased with solution concentration. However, it decreased with increasing temperature and NIPAM concentration in the gel. It also was found that the amount of ion desorbed from the copolymer gel decrease with increasing NIPAM concentration. Additionally, desorption ability of the copolymer gel achieved maximum value at high temperature.