Graphite coated metal (Fe@G, Co@G, Ni@G) nanoparticles were prepared by a detonation method using ethanol, urea, RDX and metal source of nitrate as the composite explosive. The composition, morphology and microstructure of detonation products were analyzed by means of X-ray diffraction (XRD), transmission electron microscopy (TEM)-energy dispersive spectro-scopy(EDX) and X-ray fluorescence (XRF). To clarify the tribological properties, the lubricating mixed oils (SN150 base oil) with five different content (0%, 0.2wt%, 0.4wt%, 0.6wt% and 0.8wt%) of graphite coated metal nanoparticles were prepared, and then the four-ball tests were carried out separately. The results indicated that the product of detonation is core-shell structure with a range of 10-50nm. The core is single metal and the shell is mainly composed of graphite about 3-8nm. From the four-ball tests, the friction coefficient and wear scar diameter decrease first and then increase with the addition of graphite coated metal nanoparticles and Ni@G show the best tribological properties as a lubricant additive of graphite coated metal.