Pure alkali alumino-silicate hydrosol has been synthesized by the wet interaction of alkali silicate and alkali aluminate solution under specific experimental conditions. It was converted to different cationic forms. The cation exchange behaviour, the most important property, by which it can be differentiated from the other sols has been studied with respect to variation of the nature and concentration of cations. Under equilibrium condition, the nature of the exchange concentration relationship did not show any change in their nature, but the sequences of the cations, specially the divalent ones, were found to be dependent on the nature of both the exchanging and exchangeable cations. © 1982 Taylor & Francis Group, LLC.