In this paper, the lastest development of lower friction diamond films with regard to nucleation and growth mechanism, deposition technology and its research trend. the differences between conventional and lower friction diamond films in terms of nucleation and growth mechanism and deposition technology were compared and also, the mechanical performance of lower friction diamond films such as hardness, compressive stress, tribological properties and so on were analyzed. At last, a new method of forming composite diamond coating by depositing lower friction diamond films onto conventional films layer was put forward. CVD diamond thin films possess the unique characteristics of the native diamond such as high hardness, wear resistance, good thermal conductivity and low thermal expansion coefficient. Recently, with the development of the technique of chemical-vapor-deposited (CVD) diamond films, synthesis and characterization of diamond films have gained wide spread research interest.