The rates for the sorption of citric acid from relatively concentrated aqueous solutions (0.05∼0.2 mol/dm3) with macroporous resins containing tri-n-octylamine (TOA) were measured in finite bath. Experiments were carried out as functions of citric acid concentration in the aqueous phase, TOA concentration in the resin phase, and temperature. It was shown that the kinetic data could be well described by the Elvoich equation. Rate equations for the sorption processes were obtained and the activation energy was also determined.