To find a novel resin to remove Co(II), the adsorption behaviour of Co(II) from the simulated acid leaching solution was investigated by ion exchange with AG®50W-X4 resin. Parameters such as reaction time, HCl concentration, and resin concentration affected the loading efficiency of Co(II) by AG®50W-X4 resin were tested. The adsorption behaviour of Co(II) strongly depended on HCl and resin concentration while reaction time was little effect on the loading percentage of Co. The loading behaviour of Co(II) into the resin fitted well with the Langmuir adsorption isotherm and the loading capacity for Co(II) was found at 29.8 mg/g. Moderate HCl solution was effective in eluting Co(II) from the loaded AG®50W-X4 resin. The obtained results investigated that AG®50W-X4 resin was a promising resin to absorb Co(II) from the low acid leaching solution of the spent lithium-ion mobile phone batteries.