Thermal decomposition of Zr/KClO4 priming compositions containing different concentration of additives, such as graphite, Fe2O3 and Al2O3 have been studied by DSC/TG techniques. The firing characteristics of these primer mixtures have also been examined by Bruceton test and by adiabatic calorimeter. The results of these experiments suggest that strong interaction has been occurred between KClO4 and Fe2O3 in the solid state.