Mass transport of divalent amino acids, arginine and histidine, was investigated in an ion exchange system using DIAION SK104, SK1BL, and SK112. Ion exchange equilibrium constants of arginine were 5.0g/cm3 for SK104 (4wt% D.V.B.), 25.0g/cm3 for SK1BL (8wt% D.V.B.) and 25.0g/cm3 for SK112 (12wt% D.V.B.). The ion exchange equilibrium constant of histidine was 8.0g/cm3 for SK1BL (8wt% D.V.B.). Resin phase diffusivities of divalent amino acids are measured by batch uptake experiments. Resin phase diffusivities of divalent arginine were decreased from 9.0x10-8cm2/s to 1.6x10-8cm2/s while the D.V.B. content in resin increases from 4wt% to 12wt%. Resin phase diffusivity of histidine for 8wt% D.V.B. resin was 7.0x10-8cm2/s. The steric hindrance model was able to describe measured resin phase diffusivities.