Microscratch　test　was　conducted　on　four　different　diamond-like　carbon　(DLC)　films　by　Vickers　indenter　to　study　the　scratch　resistance　of　films　under　progressive　normal　load　linearly　increasing　from　5　mN　to　15　N.　With　the　increase　of　normal　load,　penetration　depth,　lateral　force,　residual　and　contact　scratch　widths　increase　nonlinearly;　scratch　hardness　and　lateral　hardness　decrease　nonlinearly;　scratch　friction　coefficient　increases　under　small　loads,　and　then　tends　to　be　a　constant　under　large　loads.　DLC-H　has　the　smallest　scratch　friction　coefficient　among　the　four　films,　and　different　targets　have　little　effect　on　scratch　friction　coefficient.　DLC-Si　and　DLC-Cr　have　almost　the　same　scratch　resistance　(or　penetration　depth),　and　larger　than　that　of　DLC,　whose　scratch　resistance　is　almost　the　same　as　that　of　DLC-H.　Fracture　toughness　was　obtained　by　scratch-based　methodologies:　the　additional　Si　or　Cr　target　can　enhance　fracture　properties　of　DLC　film-steel　substrate　systems,　whereas　C4H10　can　harm　fracture　properties.　Fracture　toughness　of　DLC-Si　(about　17　MPa·m1/2)　was　larger　than　that　of　DLC-Cr　(about　15　MPa·m1/2)　with　the　large　values　of　fracture　toughness　obtained　under　penetration　depth　larger　than　film　thickness　attributed　to　substrate　effect.　©　2022