Abstract: The specific surface, porosity and the pore size distribution of potassium titanium hexacyanoferrate are determined. The distribution ratio in the CsNO 3 acidic solution is investigated. The mathematical model for ion exchange kinetics in the solution of finite volume has been established. The calculated results show that ion exchange reaction mainly occurrs in the outer film of KTiFC. The ion exchange process is regarded as a shell progress reaction. The experimental results are in good agreement with the calculated values.