Chemisorption of energetic C₂ clusters on diamond(111) surface is investigated with molecular dynamics simulation and mang-body interatomic Brenner(#2) potential.At 300 K,molecular dynamics simulation are performed as a C₂ cluster bombards six different bombarding sits on diamond(111) surface at incident energies of 1 eV,20 eV,30 eV,respectively.Different chemisorption configurations are observed.Deposition of C₂ atoms are observed during the bonding collision.Influence of sits and impact energy on structure of deposited clusters are discussed.It shows that the collision processes change in different environments.Increase of cluster incident energy is apt to bond forming.