We presented a graphene-wrapped Cu particle hybrid system (G@Cu) to be used as a high performance surface-enhanced Raman scattering (SERS) substrate. The Cu particles wrapped by a few-layer graphene shell were directly synthesized on SiO2/Si by chemical vapor deposition assisted with thermal annealing in a mixture of methane and hydrogen. The detailed explanation on the different morphology of Cu particles induced by different thermal annealing condition was carried out with both qualitative and quantitative analysis and a series of G@Cu 3D models of Cu particles with different shape anisotropy and inter-particle gap were also built for further study of Raman enhancement mechanism. The G@Cu showed fine SERS activities, including the fluorescence quenching effect, the stability of Raman signals, chemical and optical stability, with an enhancement factor (EF) of ~1.5 × 106.