NOVELTY - Preparing highly sinter-stable metal nanoparticles supported on mesoporous graphitic particles, involves e.g. (a) impregnating particles having a porous basic framework with a graphitizable organic compound, (b) performing high temperature graphitization to provide a graphitic framework in the porous basic framework, (c) removing the basic framework from the particles to provide a mesoporous graphitic framework, (d) impregnating the mesoporous particles with a catalytically active metal, (e) performing hydrogenation of graphitic particles and (f) high temperature treatment of the particles.    USE - The method is useful for preparing highly sinter-stable metal nanoparticles supported on mesoporous graphitic particles (claimed), which are useful as catalysts for high temperature reactions in reducing atmosphere and cathode side oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells.    ADVANTAGE - The highly sinter-stable metal nanoparticles exhibit good thermal and chemical resistances and electrical conductivity, and improved stability of the supported metal nanoparticles and durability.    DETAILED DESCRIPTION - Preparing highly sinter-stable metal nanoparticles supported on mesoporous graphitic particles, comprises (a) impregnating particles having a porous basic framework with a graphitizable organic compound, (b) subjecting the particles obtained in step (a) to a high temperature graphitization process, to provide a graphitic framework in the porous basic framework, (c) subjecting the so-obtained graphitized particles to a process for removing the basic framework, to provide a mesoporous graphitic framework, (d) impregnating the mesoporous graphitic particles obtained in step (c) with at least one catalytically active metal salt including titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminum, molybdenum, selenium, tin, platinum, ruthenium, palladium, tungsten, Iridium, osmium, rhodium, niobium, tantalum, lead, bismuth, gold, silver, scandium and/or yttrium, (e) subjecting the graphitic mesoporous particles obtained in step (d) to a hydrogenation process to provide catalytically active metal sites on and/or in the graphitic mesoporous particles, and (f) subjecting the graphitic mesoporous particles obtained in step (e) to a high temperature treatment in a high temperature of 600-1400 degrees C, preferably up to 1000 degrees C and in an inert atmosphere. An INDEPENDENT CLAIM is included for porous graphitic bodies having highly sinter-stable metal nanoparticles in the three-dimensional pore structure.