Nanotribological characterization of amorphous hydrogenated carbon (a-C:H) films is performed by scanning probe microscopy. The a-C:H films are produced on silicon substrate by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-MPCVD). The influences of different percentages of hydrogen (H-2) and methane (CH4) in the gas-discharge plasmas on the nanotribological characteristics are investigated. Scanning probe nanotribological tests, including the nano-friction, nano-wear and nano-scratch, are carried out. Large quantitative variations of the friction coefficient as well as the wear depth are found for different H-2 content percentages in source gas. The results indicate that a higher H-2 content in the source gas is beneficial to wear and scratch resistance, and produces a lower friction coefficient and that source gas H, content plays an important role in the tribological characteristics of diamond-like films.