The effect of salt concentration on temperature-swing adsorption of nonionic surfactant Triton X-100 with poly(vinylmethylether) gel (PVMEG) was investigated with sodium salts of citrate, succinate, sulfate, hydrogen phosphate, chloride and nitrate. With increasing salt concentration, the amount of Triton X-100 adsorbed on PVMEG increased and the critical temperature range across which the adsorbed amount of Triton X-100 drastically changed shifted to the lower temperature side. The effects of salt type and concentration on temperature-swing adsorption process were evaluated in terms of effective adsorbed amount, midpoint temperature and temperature sensitivity. The effective adsorbed amount increased with increasing ionic strength up to a certain critical value depending on salt type, and then sharply decreased above the critical value. The dependency of midpoint temperature on ionic strength below the critical value was different from that above the critical value. The temperature sensitivity became minimum at ionic strength around the critical value, The critical ionic strength was found to be depend mainly on the valence of ion.