Plastic-bonded explosives (PBXs) with different amounts of polymer and based on explosives with different particle size distributions have been compared for their thermal properties and shelf life. Chung Shan Institute of Science and Technology has extensive experience with the processing of hydroxyl terminated polybutadiene (HTPB)-based PBXs. The investigation showed that the shelf life of HMX-based formulations is longer than 60 years at ambient temperature. The thermal properties of three HMX-based formulations such as specific heat, linear thermal expansion coefficient, auto-ignition temperature and kinetic parameters concerning the explosion, explosion temperature, etc. are very close with the exception of glass transition temperature.