Friction, lubrication, wear and adhesion are phenomena familiar from everyday experience. As the size of materials involved in engineering processes approach that of molecular scale (e.g., recent advances in STM and AFM for surface engineering), an atomistic understanding of the mechanism involved in friction and wear in becoming critical. Subjects of current interests include: 1) what is friction from atomistic point of view; 2) how do it depends on load; 3) how does it depends on the host materials structure (phonons, elasticity etc); 4) how does surface coating help? My interest is to approach these problems using atomistic molecular dynamics. A critical point is to design an empirical potential. This will be modeled using ab initio molecular dynamics.