Department of Chemical Technology, University of Calcutta, Calcutta-700 009 Manuscript received 7 November 1991, revised 20 November 1992, accepted 19 February 1993 12-(Calcium oxide)-7-(aluminium oxide), i.e. C12A7 is almost always present in variable proportions upto 15% in the ordinary high alumina cements and the more refactory calcium aluminate cements. The thermal stability of C12A7 hydrate in relation to titania has been studied by thermogravimetry. The dehydration rate curves obtained at different temperatures (100-400°) follow first order kinetics. The activation energy values of the dehydration reactions are found to be dependent on the titania content. A 6% titania has beneficial role on the thermal stability of the hydrated C12A7.