The aim of this work is to study the changes of hydrotalcites structure when is subjected to gradual multiple calcination/hydration treatments in the presence of water or alkaline solution with the same composition like in co-precipitation step and then to analyze its influence on the catalytic activity in the cyanoethylation reaction between ethanol and acrylonitrile with the main product being beta-ethoxypropionitrile according to these treatment. The samples were characterized by elemental analysis, XRD, DRIFT, CO2-TPD.