The eutectic compositions of eleven mixture systems (in three types) of energetic materials, including Tetryl/PETN, PETN/RDX, HMX/P Explosive and RDX/NQ, were obtained by constructing a special phase diagram for the correlation of the apparent fusion heat with the composition (HX-phase diagram). The apparent fusion heats of the systems and its eutectics as well as the eutectic temperatures were determined by differential scanning calorimetry (DSC). The results obtained from DSC were confirmed by TX-phase diagrams constructed from microscope heat stage method for these mixture systems.