The adsorption of carbon on Ni (111) surface is studied with density functional theory in this paper. The adsorption energy and density of states is calculated. We analyzed the density of states of carbon on diamond (111) surface and carbon adsorbed on Ni(111) surface, the result shows that they have similar electronic structure, namely, they both have nonbonding and bonding sp3 hybridized electrons. Furthermore, it is found that the carbon atoms on diamond (111) surface and those adsorbed on Ni(111) surface are prone to bonding and form a diamond-like structure.