Synthetically prepared calcium dialuminate samples were subjected to the hydration process at room temperature for different periods of time. Hydrated products have been identified by DTGA techniques. The thermogravimetric method has been applied to obtain dehydration rate curves in the 100-400 degrees C range and formal first-order kinetics have been followed. The activation energy values of the dehydration reactions have been determined by studying the thermal stability of the hydrated calcium dialuminate.