Abstract: Using means provided by linear algebra, a method for the mathematical identification of the thermal decomposition mechanism of cyclotetramethy-lene let rani tramine ( HMX ) i s deduced, based on the principle of conservation of mass. By this msthod tne thermal decomposition mechanism of HMX can be identified,as well as ths rates of formation of HMX decomposition products and the reduced rates of the various reactions of HMX decomposition can be calculated. The method is alco suitable for other reaction systems.