The distribution of cesium ion and the properties of ion exchange was studied in various kinds of zeolites, i.e. synthetic mordenite, natural mordenites and clinoptilolites. The distribution coefficients of cesium (K_<Cs>) exceeded 10^3 even in acidic region (pH~1), though the K_<Cs> values somewhat decreased with increasing acidity. The dynamic properties of ion exchange were examined by zeolite-column process and the break-through curves were obtained at different flow conditions. The break-through capacity, the total capacity and the column utilization increased with the increase in column temperature and with the decrease in the flow rate. Heat treatment resulted in an increase in the strength of zeolites, which was desirable for handling them. The zeolites heated at 300℃ and 500℃ increased in their total capacity of ion exchange of Cs and the granulated zeolites heated at 500℃ improved in its exchange rate and column utilization.